A student lifts a physical science book off the table and above their head. Is there work being done?

Yes

Explanation:

Work done in this situation is equal to the directional potential energy. That is to say the body has been displaced from one position to another ( in this case it has to do with height )

And so

Force × displacement= mass(gravity) × height

However,no further work is done if the person remains at that position.

6/12=1/2

step-by-step explanation:

here we know that ball will drop down by total distance 3.2 m

so here we know that

now using kinematics

now in the same time it will cover horizontal distance of 0.75 m

so speed of the ball will be