A 0.145 kg baseball is thrown horizontally at 15 m/s from a platform, so that it starts at 5.2 m above the ground. How much has its kinetic energy increased when it reaches the ground?

16 J , 24 J , 0 J , or 7.4 J

? :/

Question

A 0.145 kg baseball is thrown horizontally at 15 m/s from a platform, so that it starts at 5.2 m above the ground. How much has its kinetic energy increased when it reaches the ground?

16 J , 24 J , 0 J , or 7.4 J 

? :/

michele_laino · Answer

the initial kinetic energy is:
 $$KE = \frac{1}{2}m{v^2} = \frac{1}{2} \times 0.145 \times {15^2} = ...Joules$$

anonymous · Answer

so we get 16.3125? so our solution is 16 J?

michele_laino · Answer

that result is right! Nevertheless it is not our final answer!

anonymous · Answer

ohh okay! what is netx?

michele_laino · Answer

we have to consider that situation:
|dw:1433103218745:dw|
our ball, in free falling, has gained a vertical velocity