How High Should a Marble Be Released to Propel a Steel Ball at 150cm/s?

[darkdryad]

I'd be grateful if anyone could help me for this question

"A 100g marble rolls down a 40 degrees incline. At the bottom, just after it exits onto a horizontal table, it collides with a 200g steel ball at rest. How high above the table should the marble be released to give the steel ball a speed of 150cm/s?"

thx

 

[Tide]

What have you tried so far?

 

[marlon]

i suppose there is no friction? In that case use conservation of total energy.

Using the formula of kinetic energy you can calculate the velocity of the marble necessary to give the ball it's given velocity.

Then use conservation of energy for the marble : mgh + 0 = 1/2*m*v² + 0

At height h the velocity is 0 and at the endpoint the height is 0...