When you lift a book from the ground to your desk, what kind of work do you do, negative or positive? by lifting the book, what do you change? does the book gain or lose energy? what kind of energy?

i really only need with the last 3, but any is appreciated.

Aman does 500 j of work pushing a car a distance of 2 m. how much force does he apply? assume there is no friction. a. 250 n b. 1000 n c. 125 n d. 500 n

After a big snowfall, you take your favorite rocket-powered sled out to a wide field. the field is 195 m across, and you know that your sled accelerates at a rate of 3.65 m/s2 when the rocket is on. how much time will it take the sled to cross the field starting from rest, assuming the rocket is on the whole time?

Find v(t), given acceleration a(t)=7j and initial velocity v(0)=k