1. The problem statement, all variables and given/known data A bullet collides and embeds itself into a block hanging from a rope. The block and embedded bullet swing out to an angle of 10 degrees. If the bullet plows 2 cm into the block before stopping, what is the coefficient of kinetic friction between the block and the bullet? bullet has mass of .1 kg block on pendulum of length 1 m has mass of 5 kg 2. Relevant equations momentum conservation, energy conservation, newtons laws 3. The attempt at a solution I found the initial velocity of the bullet, 273.386 m/s^2, using momentum and energy conservation. Thought maybe I could use, vf^2 = vi^2 + 2ax, which I guess tells me that the bullet after collision had an acceleration in the x direction of -1,868,500 m/s^2 with respect to the frame of reference of the pendulum+embedded bullet. I thought maybe I would then use F=ma.