Experiment 6:
Blackwood Ballistic Pendulum
September 18, 2013
Jamal Wright
Zachary Floyd
Christopher Wilson

Experiment 6
Blackwood Ballistic Pendulum
Jamal Wright, Zachary Floyd, Christopher Wilson

Abstract Our goal of this experiment is to determine muzzle velocity by two methods: 1) employing uniform linear motion relations, the kinematic equations; 2) using the principles of conservation of energy and momentum. In this paper, we aim to validate the law of conservation of momentum. We do so by comparing results from two experiments conducted with a single ballistic launcher/pendulum apparatus.
Hypothesis: The initial velocity of a ballistic pendulum can be determined using the law of conservation of momentum. Momentum should be conserved, based on the law of conservation of energy. If momentum is conserved, the velocity found using the law of conservation of momentum equation should equal the velocity found using projectile motion. Due to the law of conservation of momentum, the total momentum before the pendulum is swung equals the net momentum after the pendulum is swung.
Introduction/Purpose
The ballistic pendulum is a device where a ball is shot into and captured by a pendulum. The pendulum is initially at rest but acquires energy from the collision with the ball. Using conservation of energy it is possible to find the initial velocity of the ball. In this ball-pendulum system we cannot use the conservation of mechanical energy to relate the quantities because energy is transferred from mechanical to nonconservative forces. In the absence of external forces, the momentum of the system does not change no matter how complicated the collision. The initial momentum is always equal to the final momentum.

Figure 1: Experimental Setup for Part 1 In the first part of the experiment, the velocity of the projectile will be determined by using