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 4
 Homework Statement

A solid ball rolls smoothly from rest (At 6m) until it leaves the ramp (at 2m). How far horizontally from point 'a' does the ball hit the ground?
Hint: Smooth rolling means it does not slide.
 Homework Equations

v = ωr
a = αr
##K = \frac {1}{2}Iω^2 + \frac {1}{2}mv^2##
Figure of the problem.
There are many exercises like these, and I've read the whole chapter and I got no clue where to start here.
Kinetic energy from gravity is: E = mgh = 39.3m
I could try change v to ωr in the K equation but it will leave me nowhere because I don't have the mass nor the radius of the ball.
I'm obviously looking for the velocity at point v, assuming it has no vertical component (altho that's not specified either), but I have no way of getting it.
Anyone has a clue what to do here?