Question

A 1100 kg car accelerates from rest to 27 m/s in 6.0 seconds. Neglecting friction, hat is the average power consumption in horsepower?

Answer 1

a = (V-Vo)/t = (27-0)/6 = 4.5 m/s^2.

d = 0.5a*t^2 = 0.5*4.5*6^2 = 81 m.

Power = F*d/t = Mg*d/t = 1100*9.8*81/6 =
145,530 J/s. = 145,530 Watts.

hp = 145,530/746 = 195.1.

Answer 2

P = 0.5M*V^2/6 = 0.5*1100*27^2/6 = 66,825 J/s = 66,825 W.

hp = 66825/746 = 89.6.