Mastering Physics: Collision on an incline plane and perfectly inelastic collision

cde42003

Can anyone help me with theses problems?

1. A 500 g cart is released from rest 1.0 m from the bottom of a frictionless, 30 ramp. The cart rolls down the ramp and bounces off a rubber block at the bottom. The figure shows the force during the collision.

After the cart bounces, how far does it roll back up the ramp?

On this one I know I need to solve for the velocities before and after the collision and then use this value to get the distance, but I am not sure as to how I need to do this. I don't really know how to get the acceleration.

2. In a military test, a 575 kg unmanned spy plane is traveling north at an altitude of 2700 m and a speed of 450 m/s. It is intercepted by a 1280 kg rocket traveling east at 725 m/s.

If the rocket and the spy plane become enmeshed in a tangled mess, how far from the point of impact do they hit the ground?

This problem really has me puzzled. I tried to use the m1v1 + m2v2= m(1+2)v equation and solve for the magnitude of the velocity but am not sure where to go from there. Let me know where I went wrong. Thanks

Attached Thumbnails

 

physicsCU

On the second one, you use the final velocity from the momentum equation and use that as the inital velocity in a projectile motion problem.

On the first one, use a = gsin(theta) to get acceleration along the ramp.

Hopefully these will help you go forward.

cde42003

Ok so when you use gsin(theta) as the acceleration, and find the velocity before the collision, do you plug this into the equation for an impulse (P2=J+P1)?

On the second one, once you find the magnitude of the velocity you need to use the x and y components of the velocity in the projectile motion equations correct?