# Ballistic Pendulum

Topics: Kinetic energy, Angular momentum, Classical mechanics Pages: 3 (542 words) Published: December 10, 2013
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Purpose:
This lab will allow students to learn about angular velocity by experimenting with a PASCO pendulum set-up and DataStudio. Students will gather measurements and data and apply them to various equations, and then compare the results they have received.

Introduction: The goals of this lab are as follows:
To allow students to gain understanding of angular velocity in terms of angular momentum and rotational kinetic energy. This is achieved by using a ballistic pendulum (pictured below)and DataStudio.

Compare the results of the experiment to what the results should be mathematically.

Materials:
PASCO ballistic pendulum
Metal Ball
Electric Scale
Stop Watch
Photo-gate
Computer with DataStudio
Ruler
Procedure:
1. Measure the mass of the ball
2. Place the ball inside the pendulum arm and find the mass, and the radius from the center of mass to the end of the arm 3. Calculate the period of oscillation using a stopwatch
4. Calculate moment of inertia using the equations shown in results 5. Set up the photogate so the launched ball can pass through it 6. Launch the ball ten times and find the average initial velocity 7. Calculate angular velocity

8. Launch the ball into the pendulum and record the angle it reaches using the angle measure on the pendulum 9. Repeat step 8 ten times and find the average angle
10. Calculate experimental angular velocity and compare to the number obtained in step 7

Data/Results:
Mass of Ball (kg)
Mass of Ball + Pendulum (kg)
Radius of Pendulum to Center of mass (m)
Av. Launch Angle
Average Velocity (m/s)
Period (sec)
0.055
0.151
0.022
0.3
45.05º
8.569
1.209

Calculations:
Inertia

Conservation of Energy

Angular Momentum

Here is a table showing the results:

Moment of Inertia
Angular velocity (CoE)
Angular Velocity (Ang. Mom.)
0.0164 kgm2

Discussion:
Elastic collisions occur when two objects collide and conserve...