Question

Physics Homework

A baseball is thrown straight up with initial speed If air resistance cannot be ignored, when the ball returns to its initial height its speed is less than Explain why, using energy concepts.

Answer 1

Basically, the ball is giving up energy to the air molecules as it smacks into them. Thus, it never reaches the height it would if all K became U. So, first up, it doesn

Answer 2

Work done by all forces = change in kinetic energy

Work done by gravity + WOrk done by frictional forces= change in kinetic energy

0 + W_Friction = 1/2 *m(v_final)2 - 1/2* m(v_initial)^2

But friction does work on both the upper path and the down path... so but it's negative..

SO, final velocity is less than initial velocuty