Atennis ball is thrown vertically upward with an initial velocity of +8.0 m/s. what will the ball's speed be when it returns to its starting point?

Final speed of the ball, v = -8 m/s  

Explanation:

It is given that,

Initial velocity of the ball, u = +8 m/s

Let v is the speed of the ball when it returns to its starting point. When it returns back to its starting point, the speed of the ball remains the same only its direction changes.

Let positive direction shows upward side and negative direction shows the downward side. So, the speed of the ball when it returns to its starting point is (-8 m/s).

Hence, this is the required solution.