165n each stroke pulling 0.800m how much work does he do with each stroke

Need in all of themmm only answer if you know plsssss

A1200 kg car traveling north at 10 m/s is rear-ended by a 2000 kg truck traveling at 30 m/s. what is the total momentum before and after the collision?

How does the amount of energy required to hold each proton and neutron in the nucleus compare to the energy released when they are removed?