Physics: Projectile Motion Lab with Ballistic Pendulums
Name______Date______
Objective: To determine the speed with which a ball is shot from a ballistic pendulum.
Materials: ballistic pendulum, ball bearing, meter stick
Procedure:
1. Load your ball into the ballistic pendulum to the long range position.
2. Fire your ball. Wherever it lands, tape a piece of paper to the floor.
3. Fire your ball 10 more times onto the paper.
4. Measure the distance from the muzzle of the pendulum to the edge of the counter.
5. Measure the distance from the point directly under the edge of the counter to each of the 10 marks on your paper.
6. Add the distance in #4 to the distances in #5 to find your total distance.
7. Find the average distance the ball traveled by adding up the 10 total distances and dividing by 10.
8. Measure how high the bottom of the muzzle is off the ground.
9. Use the measurements to calculate the time the ball was in the air and the velocity with which it left the muzzle of the ballistic pendulum.
Data:
Trial / Distance from end of muzzle to edge of counter (m) / Distance from point directly below edge of counter to each mark (m) / Total distance (m)(Add the second and third columns)
1
2
3
4
5
6
7
8
9
10
Average
Height of bottom of muzzle from the floor (m) ______
Results:
1) To find the speed with which the ball is shot out from the ballistic pendulum, first use the x = vot + ½ a t2 formula to find out how long the ball was in the air. Please show this work below:
Time ball is in the air (s) ______
2) Now find the speed with which it was shot by using the formula v = x/t. Use your average total distance for x and the time you found for the ball being in the air for t to find your speed. Please show this work below:
Velocity of the ball shot from the ballistic pendulum (m/s) ______
Conclusion (part 1): Did any of your calculations surprise you? Explain. How accurate do you think your answers were? Discuss your answer including any sources of error you might have had.
Now repeat the experiment using ping-pong balls instead of the steel ball bearings:
Data:
Trial / Distance from end of muzzle to edge of counter (m) / Distance from point directly below edge of counter to each mark (m) / Total distance (m)(Add the second and third columns)
1
2
3
4
5
6
7
8
9
10
Average
Please show your work for the following:
Time ball is in the air (s) ______
Velocity of the ball shot from the ballistic pendulum (m/s) ______
Conclusion (Part 2): What, if any, differences did you observe between the ball bearing’s data and the ping-pong ball’s? Explain.