Here's a problem that I've been having trouble on for awhile and seem to be stuck. I was just wondering if someone could guide me or show me how to do this problem. The Ballistic pendulum is a device usd to measure the speed of a fast-moving projectile such as a bullet. The bullet is fired into a large block of wood suspended from some light wires. The bullet is stopped by the block, and the entire system swings through the vertical distance, h. The mass of the bullet (m1=0.068kg), the mass of the pendulum (m2=0.256kg), h=6.2cm. Vo=(.324kg/.068kg) x (2 x 9.8 m/s^2 x .062m)^1/2 = 5.25m/s KEinitial= 1/2(.068kg x 5.25m/s)^2 = 0.937J KEfinal= 1/2(.324kg) x (2 x 9.8 m/s^2 x .062m) = .197J I got that far. I was wondering how do I find the kinetic energy lost from the info?