Impulse exerted on car during collision

[naianator]

Homework Statement

Two cars are approaching a perpendicular intersection without a stop sign. Car 1 has a mass m1=900kg and is heading north at v1=25m/s. Car 2 has mass m2=700kg and is heading west at an unknown speed v2. The two cars collide at the intersection, and stick together as a result of the collision. The police report stated that after the collision, the two cars moved together in a direction 40∘ west of north and stopped after sliding d=35m from the collision point.

What is the magnitude of the impulse exerted on car 1 during the collision?

What is the magnitude of the impulse exerted on car 2 during the collision?

Homework Equations

x(t) = x_o+v_o*t+1/2*a*t^2
mv = m1v_1'+m2v_2'
J = mv_f - mv_o

The Attempt at a Solution

Velocity of car 2:
26.9711 m/s

Velocity after collision:
18.35729 m/s

Momentum of car 1 before collision: 22500 kg m/s

Momentum after collision: 1600 kg * 18.35729 = 29371.664 kg m/s

sqrt((29371.664)^2 - (22500)^2) = 18879.7
(which is equal to the momentum of car 2)

If I can figure out the first one I can do the second one I just need to know what I'm doing wrong.

 

[BvU]

In PF you want to show what you did to get these numbers...
I can follow this one, but generally it's impossible to find what goes wrong where ...

Momentum of car 1 before collision: 22500 kg m/s

Momentum after collision: 1600 kg * 18.35729 = 29371.664 kg m/s

Yes, but what is the momentum of car 1 after the collision ?
And then you want to make a drawing to see what the change of momentum for car 1 is.

 

[naianator]

In PF you want to show what you did to get these numbers...
I can follow this one, but generally it's impossible to find what goes wrong where ...

Yes, but what is the momentum of car 1 after the collision ?
And then you want to make a drawing to see what the change of momentum for car 1 is.

Would that be 18.35729*900 = 16521.6? Because 16521.6^2-22500^2 is a negative. Should I just use 16521.6sin40 = 10619.9?

 

[naianator]

Would that be 18.35729*900 = 16521.6? Because 16521.6^2-22500^2 is a negative. Should I just use 16521.6sin40 = 10619.9?

thats velocity after collision*mass of car 1*sin(theta)

 

[BvU]

What does the drawing tell you ? Do you realize that momentum is a vector ? It has two components !