How to find retarding force ?

Question

a 950 kg car has a motor that can deliver a power of 3.36(times sign) 10^4 j/s to move the car forward.The maximum constant speed of the car on a level road is 100km/h.how large a retarding force acts on the car at that speed ???

Answer 1

Power ,P=FΔV

Here F is the retarding force and ΔV speed of the car

3.36*10^4=F*100*5/18

F=3.36*10^4*18/(500)

  =1209.6 N

 =1.2096 kN