1 Kinematics: Motion

• The tailgating rule is supposed to be followed when you drive.

• If the car in front stops abruptly, use significant digits in calcula to avoid a collision.
• If you are three seconds behind.

• A collision is likely if you are less than 3 seconds away.
• The 3-second rule is explained in this chapter.

• In the northern hemisphere, we have more hours of daylight in June than in December.
• It's the opposite in the southern hemisphere.
• Most people accept this fact.
• Scientists want explanations for simple phenomena.
• In this chapter, we learn to describe a phenomenon that we encounter every day.

• An object's motion is described by different observers.

• Jan observes a ball in her hands as she walks across the room.
• Tim is sitting at a desk.

• Without taking her ball's position, Jan reaches the other side of the room.
• Her head did not turn as she looked from the ball.
• Tim's position does change.

• Ted and Sue are on a train.

• Ted doesn't have to turn his head to keep his eyes on Sue.
• Sue's position doesn't stand on the station platform, she turns her head to follow Sue.

• The same process can be described differently by different observers.

• The same process can be described differently by different observers.
• One person sees something moving while another doesn't.
• Both of them are correct.
• We need to identify the observer in order to describe the motion.

• Your friend first sees you in front of her, then she sees you next to her, and then she sees you behind her.
• You are moving with respect even though you are sitting in a chair.
• You are moving with respect to the sun or a bird.

• The idea of relative motion is confusing at first because people use Earth as the object of reference.
• Many people would say that an object is not moving because it doesn't respect Earth.
• It took thousands of years for scientists to understand the reason for the days and nights on Earth.
• The motion is relative.
• The motion of the Sun is explained by two ing on its axis so that different parts of its surface face it.

• The Sun is moving across the sky.

• An object of reference, a coordinate system with a scale for measuring distances, and a clock are included in a reference frame.
• If the object of reference is large and cannot be considered a point-like object, it is impor tant to specify the origin of the coordinate system.
• If you want to describe the motion of a bicyclist, you should place the origin of the coordinate system at the surface, not at Earth's center.

• simplified assumptions are made when we model objects.
• Just as we simplified an object to model it as a point, we can also do the same with a process involving motion.

• Imagine if you hadn't ridden a bike in a while.
• You would probably start by riding in a straight line.

• We want to model a car's motion on the highway.
• The car is small compared to the length of the highway, so we can assume it is a point like object.

• We start by creating a visual representation of linear motion.

• Dots are used to represent motion.

• We can represent the locations of the bags each second and let the ball roll on a smooth linoleum moving bowling ball as dots on a diagram.

• The beanbags are close together.

• The bags are push the ball harder before you let it roll, which is represented by the dots in the diagram.
• The bean was separated by a greater distance than the bags.

• The diagram shows the decreasing distance between the roll on a carpeted floor and the linoleum floor.

• The increasing distance between bags floor and gently push on it with a ball is represented by the dots in the diagram.

• The spacing of the dots allows us to see motion.

• The dots are equal in spacing when the object travels without speeding up or slowing down.

• The dots get closer when the object slows down.

• The dots get farther apart when the object moves faster.

• In the experiments in Table 1.2, the beanbags were an approximate record of where the bal was located as time passed and help us visualize the motion of the bal.
• The ball was moving in the same direction at each point.

• The bowling bal was moving fast in Experiment 4.

• The motion diagram's velocity arrows got longer.

• A motion diagram is being created.

• The position of 2 is represented by dots.

• The velocities of the ball are represented by the arrows.

• The ball is moving slowly.

• The ball is moving fast.

• The ball is moving fast.

• Conceptual Exercise 1.1 is read several times and visualized.
• Draw a sketch of what is happening when drawing a motion diagram.
• The observer should have a physics repre tion.

• When a traffic light turns green, a car at rest starts moving faster.

• Slowing down at a stoplight.
• The car is at rest until the light turns green.
• A cyclist approaching the first green light is moving with out slowing down or speeding up.
• As the stoplight turns green, she reaches the second Constant speed stoplight.

• There are two bowling balls rolling along a car and a bicycle in front of an observer.
• One of them is moving at twice the rate of the ground.
• If you put one diagram below the other.
• It will be easier to compare them when they are next to each other.

• The observer on the ground can see the motion of the car and the observer on the ground can see the motion of the bicycle.

• The car and bicycle are of interest to us.

• The motion of the car is made up of four different parts, each of which has a different answer to the question.

• The figure is below.
• The bal s are moving at a constant rate for 3 seconds.
• Slow bal is at the 2-m position and the faster ball is sitting at rest.

• The car and bicycle can be modeled as dot-like objects.
• Each motion dia gram has 11 dots, one for each second of time.
• The last two dots for the car are on top of each other, since the car was at rest from time to time.

• A motion diagram is used to represent motion.
• To determine how far a car will travel after the brakes are applied, we need to describe motion quantitatively.
• The quantities we need to describe linear motion are written in this section.

• People talk about how long a process takes and how long a reading on a clock takes.
• Physicists differentiate between the meanings of time and time interval.

• The units are minutes, hours, days, and years.

• The car is moving toward the origin.

• The path length is the length of the string.

• The magnitude of the displacement is always a positive value.
• The distance is not equal to the path length.

• We only need one coordinate axis to describe an object's changing position.

• The displacements for A and B are different, moves in the negative direction, but the distances are always positive.

• The human body is about 20 cm in thickness from the back to the front.
• We should be able to measure the person's location in about 0.1 m but not more than 1 cm.
• The accuracy can be given as 0.1 m.

• He hiked from one camp to the other.

• We learn to represent linear motion with data tables and graphs.

• The object of reference is the floor.

• The position axis points in the direction of motion from 1.00 m from the first beanbag.
• Plotting the data on a graph is one way to determine if there is a pattern.
• A position versus motion is being constructed.
• The time graph in keematics graphs is more precise.

• The position of a beanbag is represented by points on the vertical axis.

• The position increases as time goes on.
• This makes sense.

• The point on the position axis corresponds to the position of each dot.

• The position axis is at 7.26 m. The position-versus-time graph has correspondence between a motion diagram and a dot on it.

• There are two different reference frames used to represent the motion of a cyclist.

• The changing position of a bicycle rider is recorded.
• The cy reference frames use Earth as the object of reference, but clist is moving in the negative direction relative to the origins of the coordinate systems and the directions of the coordinate axis in reference frame 1. axes are not the same.
• The cyclist is moving in the positive direction relative to the ence frame when using the versus-time graph.

• The cyclist is a point-like object since he is small compared to the distance he is traveling.

• They are using the same object of reference.
• We plot the position- versus-time graphs for each observer using frame 1 of the data in the tables.
• The same motion can be seen in the graph for observer 1 and observer 2.

• The graphs look different because the reference frames are different.

• The table has time-position data for a cyclist.

• The table has time-position data for a cyclist.

• The data was collected by the third observer.

What is the position of the moving object?

• A graphical representation of motion was created in the last section.

• The object of reference is Earth.
• The data can be used to find a pattern.

• The motion of cars is graphed.

• It looks like a straight line is the most reasonable choice for the best-fit curve in both cases.

• The slope of the line representing the motion of car B is greater than 0 s and 5 s.

• B0 is 1.0 m.

• The direction of motion is indicated by the sign of the slope.

• The slope units are meters per second.
• The object's position is determined by the slope indi 20 m/s.

Is there a formal definition for velocity as a physical quantity?

• The velocity is a quantitive quantity.

• Here we divide by a number.
• In our case, the same number as long as the velocities has the same direction as the displacements.
• This position-versus-time graph shows the direction of the velocity in relation to the direction of the displacement.
• We will work with components since it is difficult to operate with vec the chapter.

• We can change it.

• A quantitative exercise is a new type of task.
• The problem-solving process includes two steps, Represent math and Solve and evaluate.
• They are here to help you practice using new equations.

• The positive sign shows that the frame has a point in it.
• The motion is only meaningful with respect to the bike relative to reference frame 2.

• 0 m + 1 m>s216 s2 is +60 m.

• The data for the cyclist's motion can be used to write the equation of motion.

• The description of motion of Why is different for an object than for a cyclist.

• Even though the observer is dots at the same location, there are different positions in each reference rection opposite to the cyclist.

• There is a new type of task below.
• The four steps of the problem-solving strategy are included in the worked examples.

• The time when you and your sister are at the puddle that is 6.0 m in front of your sister is when she is running at 2.0 ms. You are the same position.
• This is the position where you can catch up to her before she gets to you.

• We draw a sketch of sister are point-like objects.
• To sketch graphs of what is happening.
• To find your sister's position at 1 second, you need to add up your two objects.
• We chose a reference frame with Earth's speed being added to her initial position.

• Do it for 2 seconds and for 3 seconds at the same time.

• At the beginning of the process, we can describe the positions and velocities of you and your sister.
• At the origin, the initial clock reading is zero.
• The result is used to make mathematical representations of motion.
• Round the final result.

• The distance between you and your sister is shown from the graphs.
• If you did the equations, you would get 16.6 m for your sister.

• These would be less than the result calculated sister is at.
• Before your sister reaches the puddle, S (2 s) is 110.0 m2 + 12.0 m>s212.0 s2 is 14.0 m. Y (2 s) is the number of m2 and the number of s2 is the number of m.

• You are following your sister.

• 3.33333333 s and moving toward your sister.

• The number produced by our calcu lator has many more significant digits than the givens.

• The rule of thumb is that if it is the final result, you need to round this num ber to 3.3, as the answer cannot be more precise than the given information.
• Your initial position will be zero.
• The calculations are easy.
• The description of the motion of an object is usually simpler in one frame.

• We've learned to make position-versus-time graphs.
• A graph of an object's velocity could be created.
• You chase your sister.
• Earth is the ob ject of reference again.
• The component is +2.0 m>s.

• The best-fit line for each person is a horizontal straight line, since neither of their velocities are changing.

• The mud's speed is -2.0 m>s.

• We have learned how to make a graph.

• An example with positive velocity is a positive number.

• During which the motion occurred.

• She is now at 2.0 s and you are at 10.0 m. Your initial position is 110.0 + 6.02 m.

• She is 3.0 m ahead of you.

• The velocity was constant.
• How would the graph show motion?

• The point on the curve is the point at which the object is shown on the horizontal axis.

• Constantly changing instantaneous speed.

• The instantaneous and average velocities are the same for motion at con stant velocity.

• An object can change its velocity quickly or slowly.
• A new physical quantity is needed to determine the rate at which an object is changing.

• The simplest type of linear motion with changing velocity is what we want to analyze.
• Imagine a cyclist speeding up so that hislocity is increasing at a constant rate with respect to the observer on the ground.

• The graph is not horizontal.
• Imagine that rate.

• The car's speed increases in the positive direction.

• The acceleration can be positive or negative.

• As time progresses, the velocity changes as well.

• The equation involves the addition and subtraction of numbers.

• There is a negative slope.

• When making motion diagrams in Section 1.3, we did this only if we were not concerned with the lengths of the vectors.

• If an object has an acceleration of +6 m>s2, it means that its speed can be changed by +6 m>s in 1 s or by +12 m>s in 2 s.

• For example, a car is going fast for an observer on the ground, but not for the driver.

• We apply.

• Imagine that you are sitting on a bench watching a cyclist ride a bicycle on a straight road.

• We can sketch the process as we please.

• Its speed increased 1 s later.
• It is moving in a negative direction.

• The veloc ity changed by another 1.5 m>s and was now (-5.5 m>s) + (- 1.5 m>s) The bicycle sped up by 1.5 m/s each second in the negative direction.

• The car's speed is 3.0 m>s2.
• The motion dia- 0 has a velocity of +14 m>s.
• The bike's velocity is shown below.

• The direction is going in a different direction.

• It is possible for an object to have two different speeds, one positive and one negative.
• The velocity and acceleration components along the same axis have the same sign when an object is speeding up.
• The components of an object have opposite signs when they slow down.

• During that time interval, the velocity is almost constant.

• The area under the rectangle is the magnitude of the curve and the time axis.
• We can repeat the procedure many times.

• The equation should be reduced to the result from our investigation of the two areas.

• 2 appears in the book.

• The position's Displacement changes more during the same time interval.

• A woman is jumping off a boulder.

• The central part of her body was replaced with rearranged Eq.

• The sign is not positive.
• The eration and acceleration point upward if you assume constant accretion.
• The motion diagram does not allow us to model the woman as a change arrow.
• This is a point-like object.
• The unit is correct.
• We can't focus on the movement of her midsection.

• The chal enge is later that it is.

• When she first contacts the ground and when she comes to rest.

• Since we have two equations and two unknowns, we can solve Eq.

• A new equation for the acceleration was developed in the Represent Mathematical step above.
• The equation is described briefly below.

• The words in the problem statement, a sketch, one or more dia grams, and a mathematical description are some of the ways in which we will represent physical processes.
• Representations need to be consistent if they are to agree with each other.

• Two friends walk on a sidewalk as point-like objects, since the distances they move are constant.
• Jim is east of their own sizes.
• At 2.0 m/s, the motion dia you and walking away from you.
• Their motions are represented by grams below.

• Earth is the object of reference with your position as the reference point.

• The positive direction will lead to the east.
• Jim and Sarah are two objects of interest.
• Since she is moving west, the velocity is negative.

• We weren't asked to solve for more than one quantity.
• We will do it in the Try it yourself exercise.

• Jim and Sarah are both at the same position.

• It is important to understand the mathematical language of physics.
• This text helps develop this skill.
• In this type of problem, you have to work backwards: you are given one or more equations and are asked to use them to create a sketch of a process.
• You can use the sketch to create a diagram of a process that is in line with the equations and sketch.
• The equations could be used to solve the word problem.
• There are many possible word problems for a mathematical description.

• A sketch, motion diagram, kinematics graphs, and a verbal description of a situation that is con position-versus-time and velocity-versus-time is needed.
• There are many graphs of the process.
• The tions that the equation describes are the same.

• The general equation for the linear motion axis looks like a spe slope and a +5.0 m intercept.
• The object is indicated by the sign in front of the 3.0 m/s.

• Imagine that the object of reference is a run and that the equation represents positive.

• The object of reference is the runner.

• The person on the bench is moving towards the runner.

• The situation is shown in a motion diagram.
• The spacing of the dots and the lengths of the velocity arrows show that the object of interest is moving at the same rate as the observer.

• The per bench is the object of reference and observes.

• The object of the runner is a runner.
• The process is described by the interest moving toward the same equation as in the example: a person on a bench.

• An initial sketch and motion diagram should be consistent with the equation and the new object of reference.

• A consis tent motion diagram and an initial sketch are shown to the right.

• Let's apply some representation techniques to linear motion.

• A process is represented by the following interest.

• To describe a process that is consis tent with this equation, use the equation to construct an initial sketch, motion diagram, and words.

• The equation appears to be an application.
• The path it travels is the result of di.
• The car's speed and acceleration are positive.

• The van has 2 tion on it.

• Imagine that the equation describes the motion of a car passing a van on a straight highway.
• The car is moving faster than the van.
• The car goes at a rate of 2.0 m>s2 with respect to the van.
• The van is the object of reference, the positive direction is the direction in which the car and van are moving.
• There is a sketch of the situa tion.

• At the start of the Equa, there is a mathematical representation that describes the motion of a cyclist.

• The cyclist is traveling in a certain direction.
• We can check the consistency of the different observing of the cyclist when the person starts.

• They are in this case.

• We will walk you through the motion in this chapter, which represents a car's 12 others.
• An example problem has a time interval of 10 strategy.

• The object of interest is the car.
• The problem is the object of reference.
• Pick the object that interests you.

• The car is moving in a coordinate system with the plus sign.
• From the graph, we can see that the car is moving in a positive direction.

• An initial sketch is created.

• The car is modeled as a point-like object moving along a straight line.
• The magnitude of the velocity is decreasing and the velocity arrows get increasingly smal.
• We draw a diagram.

• If needed, draw motion diagrams and graphs.

• To find the answer to the question you are investigating, use the known information in the first equation to solve the equations.

• Evaluate the results to see if they are reasonable.

• The car's position when it stops is able values.

• The units are correct and the magnitudes are reasonable.

• The car should never stop in the case of zero acceleration.

• The result of dividing a nonzero quantity by zero is zero.
• It takes an infinite time for the car to stop.
• The limiting case is checked out.

• Even though the cyclist's speed decreased, the acceleration is positive.

• According to Mike, its original position is 16-48 m2 and its acceleration is 1-2.0 m.

• Explain how to correct his answer if yes.

• In this chapter, we learned about two simple models of motion--lin ear motion with constant velocity and linear motion with constant accelera tion.
• The motion of objects is a special case of linear motion.

• The following experiment is observational.
• Take out a sheet of paper from your notebook and hold it in one hand.
• Drop the text book on the floor parallel to the floor in the other hand.

• The book is the first to land.
• Drop every 0.10 s.

• They land at the same time.

• The first person to realize that it was easier to answer this question if he considered the motion of falling objects was Galileo Galilei.
• Galileo thought that free fall was the same for all objects regardless of mass and shape.

• Galileo thought that the speed of the objects was increasing as they moved closer to Earth.

• The speed increases in the simplest way if the time of flight is used.
• Galileo didn't have a video camera or a watch to test his hypothesis.

• The speed of the bal should increase with time if the hypothesis is correct.
• The origin of the coordinate axis is at the initial location of the bal.

• The average velocity is determined by dividing the displacement of the ball between consecutive times by the time interval.
• 0.200 s is (0.196 m - 0.049 m)

• A straight line is the best-fit curve for this data.
• The metal ball's motion is modeled as motion with constant acceleration.

• direction is not the same.
• The minus sign is in front of the 9.8 m>s2.

• The table has position and time data for a ball.

• A motion diagram is the same at all clock readings.

• The positive direction is moving in the right direction.

• The slope of the line remains at rest.

• The highest point is zero.

• The highest point has an acceleration of 9.8 m/s2.

• A car is behind a van.

• The driver of the van suddenly slams on the brakes to avoid an accident.

• The driver's reaction time is 0.80 s and the car's acceleration is also 9.0 m>s2.

• We have two objects of interest and we represent this situ ation for each vehicle.

• Capital letters are used to indicate quantities referring to the van and lowercase letters are used to indicate quantities referring to the car.

• The process begins when the van stops.
• The van's final position is the driver starting to brake.

• The front bumper of the car is where the position of the car is.
• The van's position is determined by its 45 m rear bumper.

• There is a 55 m graph line for each vehi cle.

• The van would stop about 10 m from where the car would stop.
• The distance the van travels while stopped can be determined by the equation.

• The car traveled at 25-m/s constant velocity.

• The car is traveling at 18 m/s.
• The van was moving slower than usual.
• When the car started to brake, the subscript 0 was the car.
• When the driver sees the van start slow, they both slowed down at the same rate.
• The subscript 1 shows when the car's speed was greater than the driver's.

• The eling was at 30 m/s.

• The car slows down at a rate of 10 m>s2 after applying the brakes.
• The second car has a 1.0-s reaction time according to the subscript 2.
• The car stops moving.
• This part of speed has decreased to 20 m/s.

• Explain why tailgating accidents occur.

• The general elements of physics knowledge should be matched with the appropriate examples.

• I woke up at 7 am.

• The point-like object (3) was born on November 26.

• He should have a free fall.

• Rolling ball is a physical phenomenon.

• Figure Q1.10 shows a graph for a moving object.

• When the object moves at constant velocity, a sandbag hangs from a rope attached to a hot air bal.
• The rope connecting the bag to the bal oon is cut.
• Observer 1 is in a hot air balloon while observer 2 is on the ground.

• A second small ball is dropped by you.
• When 1 and 2 see it go up and down.

• An apple falls.

• There are two small metal balls in your possession.

• The car is travelling at 12 m/s.
• The origin of statements that are not correct is a stoplight.

• Your car's speed decreases when you apply the brakes.

• You throw a smal bal.
• The correct statement should be chosen.

• It did 6.0 m/s2 in flight for the first time.

• You notice the time it takes to come back when you throw a small ball upward.

• He has a speed of 13 m/s.

• You can give an example of each.

• The object of reference should be specified.

• Give an example if that is the case.

• Give an example if that is the case.

• Your sister has a toy truck.

• You throw a ball.

• You need to figure out the time interval in seconds to solve the problem.

• The level of difficulty of the problem is indicated by the information.

• The speed at which the speedometer reads is 65 miles per hour.

• A car starts at rest and goes fast.
• It was km/h and m/s.
• Then it slows down until it reaches the next stoplight.
• Represent the motion with a mo jet aircraft that can travel at three times the speed of sound.

• Estimate the rate at which your hair grows.
• You are watching the ground.
• Indicate any assumptions you made.

• A man is looking through a slit in a van in opposite directions.

• She knows the distance between the two exits is 1.6 km.

• A car is moving fast.

• You can make a map of the path from where you live.
• Represent the situation with a diagram.

• A hat falls off a man's head.
• Draw a reach the classroom from where you live and your average motion diagram representing the motion of the hat as seen by speed.

• You drive 100 km east, do some sightseeing, and then turn where each observer is and what she is doing.
• You stop for lunch when you drive 50 km west.

• The interval within which the initial position object of reference and coordinate axis is known is determined by choosing an its.

• Your friend took 17,000 steps in 6.

• Two friends were caught in a storm.

• They saw lightning from a distant cloud four seconds later.
• The axis should be changed so that thunder can be heard.

• Use significant digits as 8 to write your answer.
• The front door is where you recorded your position.

• The data should be examined.

• You can use a position-versus-time graph.

• The planet Earth is 4.22 0.01 light-years away.

• Determine the length of 1 light-year and convert it to meters.

• Spaceships traveling to other planets in the solar system move at an average speed.

• Jim is 300 m ahead of the patrol car.

• If Xena's position is zero and Gabriele's position is 3.0, you run the final third at a speed of 6.0 miles per hour.

• A car is going 100 km.
• At an average speed of 50 km/h, it travels the first 50 km.

• When 100 m apart, Jane and Bob see each other.

• The observer should be specified.

• A car goes from rest to 10 m/s in 30 seconds.

• Gabriele enters an east-west straight bike path at 3.0 km and rides west at a constant speed of 8.0 m/s.

• The time where the speed limit is 25 m/s (55 mph) is determined by the average speed of the two cars during the collision.
• A highway patrol interval needed to stop and the stopping distance for each car car observes him pass and quickly reaches a speed of 36 m/s.

• The reference frame should be specified.

• A bus leaves an intersection.
• Indicate any assumptions you made.

• A jogger is running at a fast pace.
• The bus is going from a speed of +6 m/s to +20.0 m/s in 8.0 seconds.
• Determine its jogger's speed with the same speed.

• A person's motion is seen by another person.

• If her racket pushed the ball for a distance of 0.10 m. When the person's speed becomes zero, what was the time interval for the racket-ball?

• Lance was cycling at 10 m/s.
• The distance record for being shot from a cannon magnitude 1.2 m>s2 was set by David "Cannonbal" Smith in 1998.
• What do you have to do to get to (56.64 m)?

• An automobile engineer found that the bumper of the truck was 180 m>s2 because of the impact that creased from 80 km/h to zero with an average acceleration liding of 16 km/h.
• What do you know about Smith's flight indent?
• The truck stopped.

• The leader of the 40 was Col. John Stapp.
• On Stapp's final sled run, point in different directions, allowing them to change sleds at a speed of 284.4 m/s.
• They can accelerate to 1.2 m>s2 when swimming at a speed of 0.15 m/s or stopped with the aid of water brakes.
• The 0.15 m/s to 0.45 m/s is how fast he should be.

• A maximum speed of 11 m/s 41 was reached by Bolt.
• In 1977 Kitty O'Neil ran the 100m dash in 2.0 s.

• He ran the last part of the race at his maximum 20 s to stop, but he didn't know what time interval was needed to complete the race.

• A bus is moving fast.

• You want to know how fast your car goes.

• During the second 1.0 s, 6.0 m during the third 1.0 s, the runners continue to have the same acceleration.

• A car was hit by a meteorite in 1992, causing it to change speeds from -10 m/s to -20 m/s.

• You can use the graph to see their initial positions.

• Two cars are shown in a diagram.

• The clock is indicated by the number near each dot.
• When a car passes a location, an object moves so that its position changes in a second.

• Car 1 will determine when the object stops.

• Car 2 quantities concerning the motion, a story describ ing the motion consistent with the functions, and draw 64.
• There are a lot of possibilities.

• This is a two part process.

• The graphical representations are used.
• You accidentally dropped an eraser out of the window to find out where they were.
• The result should be confirmed with 15 m above the ground.

• Two cars are next to each other on a road.

• The first car is traveling at 30 m/s and the second car is traveling at 24 m/s.

• Represent the motions of the car.
• You throw a tennis ball.
• The initial speed is about 12 m/s.
• Is 12 m/s realistic for an object that you can walk on.

• While skydiving, your parachute opens and you slow down.

• 50.0 m/s to 8.0 m/s in 0.80 s.

• If you throw your helmet upward, use some reasonable numbers.
• If you hit an unpro above your hands, the helmet will rise to estimate the puck's acceleration.
• What was the initial speed of the helmet?

• You are standing in a canyon.
• The place where the rock stopped burning is where you dropped it.
• Listen to the sound of the accelera hitting the bottom.
• How deep is the rocket?
• How was your solution made?
• Take a look at their effect.

• The data can be used to determine the driver's time.
• Your friend is holding a ruler.
• You place your fingers on the sides of the ruler without touching it.

• The friend dropped the ruler without warning.
• You catch vehicles.

• When entering the water, estimate their speed and time to reach the water.

• The Leaning Tower of Pisa is 55 m high.

• A person is moving up and down in the hot air.
• At a constant speed of 7.0 m/s, the time interval needed to pass a semi-trailer bal oon needs to be estimated.
• The truck is on the highway.
• She accidentally releases the bag if you are on a two-lane highway.

• If there are any assumptions used in your estimate, tell me about them.

• You are traveling in your car on a one-way bridge.
• They are 100 m apart when they are behind the same car.
• Car A's speed decreases at 7.0 m/s each other car slams on the brakes to stop for a pedestrian who is second and Car B's speed decreases at 9.0 m/s each second.
• Do the crossing.

• The maximum speed of the cars is 0.60 s.

• You are driving a car.

• The researchers observed over two hundred thousand impacts.
• A driver with a 0.80-s reaction time applies the brakes, 423 football players at nine colleges and high schools and collected causing the car to have 7.0@m>s2 acceleration opposite the data from participants in other sports.

• Some people in a hotel are dropping water bal oons.

• The bal oons take a small amount of time to pass your window.
• The time interval below is what you made in your solution.

• The upper part of the cheek can break if a hockey 86 is accelerated.

• Is it likely that the hockey puck will hit the bone at a rate of 50 m/s, 10 m/s, 5 m/s, and 0.1 m/s?
• The Terrier-Sandhawk rocket was flown on May 11, 1970 from the correct value and the col ision lasted 0.01 s.

• The answer is close to the head's stopping distance.

• It is possible to detect X-ray sources in the atmosphere, but it is not possible to detect a 1000 m>s2 head acceleration on Earth.

• The rocket can see the X-ray sources more easily if it has a shorter impact time interval.
• The longer impact time interval is closer to them.

• The X-rays 4 show that Earth is much shorter than a rocket.
• It affects it less if the stopping distance is longer.

• Terrier-Sandhawk 6 was launched during fuel burn.

• The atmosphere absorbs the X-rays.
• The Terrier-Sandhawk rocket reached its maximum sphere 200 km or more above Earth's surface, so the number below is closest to the time interval after blast.