A car must do work at a rate of 19 kW to maintain a constant speed of 29 m/s on flat ground. How large are the forces opposing its motion ? (In units of N)

Power = 19kW = 19000W = 19,000 Joules/s.

Power = F*V = F * 29 = 19,000 J./s
F = 19,000/29 = 655.2 N.