Question

Pendulum inelastic collision - Check answers

Answer 1

You can do this with energy analysis alone.
The velocity of the ball at the bottom will be from
K.E. = (1/2) m v^2 = m g h, where h is the height that the ball is at initially.

Next, calculate h' from the angle of the two together,
and use conservation of energy,

m g h = (m+M) g h'

where M is the mass of the second ball. I have not done it, but if you did, you should have the right answer

Answer 2

M=3.79kg?