Question

Position, Velocity & Acceleration II The following problem describes a motion. Complete the table by separating the motion into parts and then specifying the signs (positive, negative or zero) of the position, velocity and acceleration of the position, velocity and acceleration remain constant during each part. ect during each part. You should choose the parts of the motion so that the signs of the A ball is sitting at rest on a table. A short time later, a woman pocket! Bumper strikes the ball with a pool cue. The ball rolls without friction until it hits a bumper at the far end of the table. The ball bounces off of the bumper and rolls back past its starting point. Complete 0m Im 2m the table for the interval between when the ball is initially at rest and when it rolls back past its starting point. Position Velocity Acceleration

Answer 1

Accelahaki slask Ssump tion Jaken →Displacement %); hve displacement posi tive and a) ckive dis placement a nagekive

Explanations:

i) Initially the ball is at rest so all quantities are zero.

ii) When the que hits the ball, it gets accelerated from rest so acceleration is positve, but at rest the position and velocity will be zero.

iii) When the ball passes 1m mark, there is no driving force so acceleration is zero, since the ball is in motion so velocity and position is positive.

iv) When the ball hits the bumper, the ball stops for a moment before moving in revrse direction. At this moment, the ball is at rest so the velocity is zero. Since the ball is far from its initial position so position is positive. Since the ball feels a force from the bumper which will make it move in reverse direction, so the acceleration is negitive as it is directed along the negetive axis(negetive according to assumpions taken).

v) When the ball again passes 1m mark, since there is no driving force so acceleration is zero. Since there is motion in reverse direction so velocity is negetive. The ball is still displaced in the positive direction so position is positive.

vi) When the ball roll back its initial position, since there is no driving force so acceleration is zero. Since there is motion in reverse direction so velocity is negetive. The ball is displaced in negetive direction, so position is negetive.