a ball is thrown upward at 25 m/s from the ground. what is the average velocity and average speed of the ball after 5 seconds?

When the ball reaches the highest point, its velocity will be zero. So final velocity is v=0m/s
Here, the time to reach highest point is equal to time to hit ground from highest point.
Consider upward motion, the acceleration of the ball is a=−g=−9.8m/s
2
(minus for motion opposite to gravity)
If t be the required time.
Using v=u+at,
0=25+(−9.8)t
⟹ t=2.5s
Thus the ball hits the ground after 2.5 seconds after reaching its highest point.

    5.5 n======    assuming that      we have      m = 0.145 kg    a = 38 m/s²therefore    5.51 n, but two significant figures.final answer: 5.5 n