What Happens When a Sliding Block Collides with Another on a Flat Surface?

[lando45]

Hey,

I got this question, and I don't really know how to solve it, I'm stuck:

A block of mass m = 2.80 kg slides down a 30.0° incline which is 3.60 m high. At the bottom, it strikes a block of mass M = 6.80 kg which is at rest on a horizontal surface, Fig. 7-41. (Assume a smooth transition at the bottom of the incline, an elastic collision, and ignore friction.)

Determine the speeds of the two blocks after the collision.

I worked out the length traveled down the slope using basic trigonometry and got a value of 7.2m, but now I am completely lost and don't know what the next step is...any help?

Thanks a lot,

Rory

 

[Tide]

Start by finding the speed of the small block using energy conservation and go from there. :)