In a long distance race, the athletes were expected to take four rounds of the track such that the line of finish was the same as the track was 200 m. (i) What is the total distance to be covered by the athletes? (ii) What is the displacement of the athletes when they touch the finish line? (iii) Is the motion of the athletes uniform or non uniform? (iv) Is the distance moved by and displacement of athletes at the end of the race equal?

1) The track is 200 meters long, the athletes do 4 rounds, so the total distance ran is:

4*200 meters = 800 meters

2) The displacement is defined as the difference between the final position and the initial position.

When you are in a track, and you run a full round, you end in the same position where you started, so the total displacement is 0 meters.

3) As they are running in a closed track (for example, a circular track), they must change the direction of motion at some point, so the motion is not uniform (uniform motion happens when the movement is always in the same direction and always at the same speed)

4) no, is not equal because in the end, the total distance is 800 meters and the displacement is 0 meters.

the independent variable, the one that is intentionally manipulated, is whether or not the car hits the barrier.

the dependent variable, the one that you measure the response in, is the distance that the washers travel.

acceleration = (change in speed) / (time for the change)

change in speed = (20-120)= -100 m/s.

1.5 min = 90 sec

acceleration = -100/90 = -1.11 m/s^2.

we don't care about the 150kg or the 2,500 meters. they don't make any difference.

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