Question

How to find the velocity of the car after collision?

Can someone please explain to me how to do question 4? Thanks!

Answer 1

They continue on at a speed of 6 m/s.

Explanation:

Momentum is conserved.
Momentum before = Momentum after

Let the mass and initial velocity of the moving car be `m_1 and u_1`.
Let the mass and initial velocity of the stationary car be `m_2 and u_2`.
Finally, let the mass and velocity of the wreckage, immediately after the collision, be `m_1 + m_2 "and v`.
Since the momentum of a mass moving with velocity is mass*velocity, and as I said above,

Momentum before = Momentum after

`m_1*u_1 + m_2*u_2 = (m_1 + m_2)*v`

`1500 kg*10 m/s + 1000 kg*0 = (1500 kg + 1000 kg)*v`

`v = (15,000 kg*m/s)/(2500 kg) = 6 m/s`

I hope this helps,
Steve