prelim physics question, help quick (1 Viewer)

[astroman]

hey got a question that need working out to:

a driver of mass 75kg, travelling in a 1200kg car collides with a stationary police car with total mass of 1500kg. the tangled wreck moves off after the collision at 8.0ms^-1. assuming negligible force on both vehicled:

a) calculate the speed of the travelling car before it hit the police car.
b) calculate the impuse on the police car due to the collision.
c) if the duration of the collision is 0.10s, calculate teh average net force applied to the police car.

thx, need working out.

 

[2xL]

mass car 1 = 1200kg. v1 = ?
mass car 2 = 1500kg. v2 = 0
Combined mass (mC) after collision = m1 + m2 = 2700kg.
Velocity after (vC) after collision = 8ms^-1.

Apply m1v1 + m2v2 = mCvC, and solve for v1. (Law of Conservation of Momentum)

Impulse = Change in momentum = m(v-u) = 1500(8-0) =

Average net force = ma = m(v-u/t) = 1500(8/0.1) =

 

[astroman]

thx