27) D

Height of car after 50m = 50/20 = 2.5

PE = mgh
PE = 800 x 10 x 2.5
PE = 8000 x 2.5 = 20,000J

Force of engine against friction = 500N
Work done against friction = Force x distance = 500 x 50 = 25,000J

Total work done = 20,000 + 25,000 = 45,000J = 45 kJ