Is Momentum Conserved in a Two-Object Collision?

[sweedeljoseph]

Homework Statement

Two objects of masses M₁ = 1 kilogram and M₂ = 4 kilograms are free to slide on a horizontal frictionless surface. The objects collide and the magnitudes and directions of the velocities of the two objects before and after the collision are shown on the diagram below. (sin 37\circ = 0.6, cos 37\circ = 0.8, tan37\circ = 0.75).

*PICTURE ISNT WORKING SO HERES THE LINK*
http://img359.imageshack.us/img359/1051/probfk9.jpg

a) Calculate the x and y components (p_x and p_y, respectively) of the momenta of the two objects before and after the collision.
b) Show, using the data from the previous question, that linear momentum is conserved in this collision.
c) Calculate the kinetic energy of the two-object system before and after the collision.
d) Is kinetic energy conserved in the collision?

Homework Equations

p=mv
m₁*v₁+m₂*v₂=m₁'*v₁'+m₂'*v₂'
ke=1/2mv²

The Attempt at a Solution

i don't have all the answers from the teacher. i know how to do part a. but that's it. i don't know what else I am supposed to do after that.

the answer to part a is:
http://img262.imageshack.us/img262/4028/charttw5.jpg
you just use the p=mv to solve for everything.

i don't know how to do the rest. i think youre supposed to use the other formula i gave but i don't know. i need a lot of help.

thank you!
sweedeljoseph

 

[Hootenanny]

You simply need to do what the question says, can you calculate the kinetic energy of the system before the collision?