A car of mass 650 kg is moving at a speed of 0.7 m/s. A man pushes the car, increasing the speed to 2.2 m/s. How much work did the man do?

By the work energy theorem the work he did is equal to the change in energy of the car.

E = (1/2) m[ (v2) ^2 - (v1) ^2]

E=325 (2.2^2-0.7^2)

E=325 (4.35)

E=1413.75J

This is the car's increase in energy and is thus how much work the man did.