Question

An 835 kg dragster accelerates from rest to 110 km/h in 0.90 seconds.

a. what is the change in momentum of the car?
b. what is the average force exerted on the car?
c. what exerts that force?

Answer 1

given,

mass of the dragster = 835 Kg

initial speed, u = 0 m/s

final speed, v = 110 km/h = 110 x 0.278 = 30.58 m/s

time, t = 0.90 s

a) Change in momentum

Δ P = m v - m u

Δ P = 835 x ( 30.58 - 0 )

Δ P = 25534.3 kg.m/s

b) average force exerted on the car

change in momentum = Force x time

25534.3 = F x 0.9

F = 28371.44 N

c) The exerted force is due to friction because the motion of the dragster is because of friction.