A simple way to measure the speed of a bullet is with a ballistic pendulum. This consists of a wooden block mass, M, into which the bullet mass, m, is shot. The block is suspended from cables of length, l, and the impact of the bullet causes it to swing through a maximum angle, A. The initial speed of the bullet is v.
a) How fast is the block moving immediately after the bullet comes to rest? (Assume this happens quickly)
b) Show how to find the velocity of the bullet by measuring m, M, l, and A.© BrainMass Inc. brainmass.com March 4, 2021, 5:40 pm ad1c9bdddf
The momentum of the bullet (m1v1) before the collision with the block has to equal the momentum of the block-bullet system after the collision. The collision between the block and the bullet is inelastic, so kinetic energy (KE) is not conserved. However, we will assume a swinging frictionless pendulum after being struck by the bullet, thus conserving mechanical energy (ME).
<br>The increase in gravitational potential ...
A simple step by step answer to this interesting question. The speed of a bullet measured using ballistic pendulum are determined.