A ball thrown upwards reaches a maximum height and then comes back down to the original level. As the ball is going upwards
A) the velocity and acceleration both point up.
B) the velocity points up and the acceleration down.
C) the velocity points down and the acceleration up.
D) the velocity and acceleration both point down.
E) the acceleration is zero.

Question

A ball thrown upwards reaches a maximum height and then comes back down to the original level.  As the ball is going upwards
A) the velocity and acceleration both point up.
B) the velocity points up and the acceleration down.
C) the velocity points down and the acceleration up.
D) the velocity and acceleration both point down.
E) the acceleration is zero.

Quizplus · Accepted Answer

As the ball is going upwards, it is moving against the force of gravity which is pulling it down. Therefore, the velocity points up (opposite to the direction of the acceleration due to gravity) and the acceleration points down towards the center of the earth. This means that the acceleration is negative (i.e. -9.8 m/s^2) while the velocity is positive (i.e. increasing in the upward direction). At the highest point, the velocity becomes zero (since the ball momentarily stops) and then starts decreasing in the downward direction, while the acceleration remains downwards.

A Ball Thrown Upwards Reaches a Maximum Height and Then