Question

A ball is thrown up with a speed of $9.8m{s}^{-1}$. What is the acceleration while the ball is moving upward?

Answer 1

1. When a body is thrown up, the only force acting on it is gravity and the acceleration of the body is the acceleration due to gravity which is $9.8m{s}^{-2}$.

2. The acceleration due to gravity is always directed towards the center of the earth but the ball is thrown upward, the direction of acceleration is opposite to the direction of motion of the ball. So, the acceleration due to gravity is taken as negative which is equal to $-9.8m{s}^{-2}$.

Hence, the acceleration while the ball is moving upward is $-9.8m{s}^{-2}$.