Momentum - Elastic Collisions?

Question

I have no idea how to approach the following problem. Any help is appreciated. I know the equations for elastic collisions already, but I don't know how to apply them to this problem.

A small ball of mass m is aligned above a larger ball of mass M = 0.71 kg (with a slight separation, as with the baseball and basketball of Figure 9-67a(see link below)), and the two are dropped simultaneously from height h = 1.5 m. (Assume the radius of each ball is negligible relative to h.)

http://www.webassign.net/hrw/hrw7_9-67.gif

(a) If the larger ball rebounds elastically from the floor and then the small ball rebounds elastically from the larger ball, what value of m results in the larger ball stopping when it collides with the small ball?

(b) What height does the small ball then reach (Figure 9-67b)?

Answer 1

Hi. The small ball will shoot up with the combined momentum of both. This is a classic experiment. But look at this. : http://thatvideosite.com/video/3907

Answer 2

this is probably not any help in any respect. a thank you to define, defining amazing as advantageous (+), given the values: m1 = 3 kg u1 = 5 m/s v1 = m2 = 5 kg u2 = -3 m/s (a) Inelastic - kinetic skill isn't conserved v * [m1 + m2] = m1u1 + m2u2 v * [ (3 kg) + (5 kg) ] = [ (3 kg) * (5 m/s) ] + [ (5 kg) * (-3 m/s) ] v * [ 8 kg ] = [ 15 kg-m/s ] + [ -15 kg-m/s ] v * [ 8 kg ] = [ 0.0 kg-m/s ] v = 0.0 kg-m/s (b) Elastic, kinetic skill is conserved [0.5*m*u^2] + [0.5*m*u^2] = [0.5*m*v^2] + [0.5*m*v^2] [0.5 * (3 kg) * (5 m/s)^2] + [0.5 * (5 kg) * (-3 m/s)^2 ] = [0.5 * (3 kg) * v^2] + [0.5 * (5 kg) * v^2] [ (a million.5 kg) * (25 m^2/s^2) ] + [ (2.5 kg) * (9 m^2/s^2) ] = [ (a million.5 kg) * v^2 ] + [ (2.5 kg) * v^2 ] [ 37.5 J ] + [ 22.5 J ] = [ (a million.5 kg) * v^2 ] + [ (2.5 kg) * v^2 ] [ 60 J ] = [ (a million.5 kg) * (v1)^2 ] + [ (2.5 kg) * (v2)^2 ] [ (v1)^2 * (a million.5 kg) ] = [ 60 J ] - [ (2.5 kg) * (v2)^2 ] (v1)^2 = [ 40 J ] - [ a million.sixty seven kg * (v2)^2 ] v1 = SQRT { [ 40 J ] - [ a million.sixty seven kg * (v2)^2 ] }