Calculating Energy Loss with Ballistic Pendulum

[paxian]

Homework Statement

How was energy lost while using the ballistic pendulum?

Homework Equations

Initial KE= 1/2mb*Vb^2 = 0.929J
Final Potential graviational = (m+M)gh= 0.198J
Energy loss = 0.929J - 0.198J= 0.731J

The Attempt at a Solution

I think the answer is:
energy lost dues to friction (air resistance) and waste heat while using the ballistic pendulum.

is this correct? Please help? Thanks a lot in advance.

 

[SammyS]

What kind of collision occurs when the ball (projectile) collides with the pendulum?