PhysicsLAB: Conservation of Momentum

Purpose: To experimentally verify that momentum is conserved during one-dimensional collisions.

Equipment needed:1 ramp with a plumb line, 1 c-clamp, 1 meter stick, 1 steel ball bearing, 1 glass marble, 2 sheets of legal paper to use as your target paper, and several sheet of carbon paper

Procedure:

Set up your ramp as shown in the illustration shown above. Clamp your ramp to the table so that it does not move during the experiment.
Tape you target paper to the floor. Using your plumb line, mark the "edge of the table" on your target paper.
Measure the mass of your steel ball and your glass marble. Record your answers in the table below.
Measure the height of your table and record it in the table below.
Place carbon paper on top of your target paper and release the steel ball 10 times from the top of the ramp. Catch the ball each time after it initially stikes the target paper. Make sure that you record only one bounce per trial. When all 10 trials are done, circle your collision points and label them:
- Part I: Steel Ball Alone
Swing out the supporting stand attached to the end of your ramp and carefully position the glass marble on its tip. Once again release the steel ball from the top of the ramp. This time both the glass marble and the steel ball will stike the paper. Make sure that you only record one bounce for each projectile. Repeat this process 10 times.
When all 10 trials are done, circle your two groups of collision points and label them:
- Part II: Steel Ball After Collision
- Part II: Glass Ball After Collision
Using your meter stick, measure the range for each of 30 impact strikes on your target paper. Record your answers in the appropriate columns in the data table provided below.
Calculate an average value for each group:
- Part I: Steel Ball Alone
- Part II: Steel Ball After Collision
- Part II: Glass Marble After Collision

Preliminary Tables:

Mass Data:

(g)

(kg)

steel bearing

glass marble

Table Data:

height of table (m)

initial vertical velocity (m/sec)

vertical acceleration (m/sec²)

Range Data:

	Part I	Part II
Trial	Steel Ball Alone	Steel Ball After	Glass Marble After
1
2
3
4
5
6
7
8
9
10

Averages

Time Calculation:

Using kinematics, determine the time required for the ball bearing and the glass marble to reach the ground. Show your calculations.

time for each ball to reach the ground (sec)

Momentum Calculations:

		Average Range (m)		Horizontal Velocity (m/sec)		Momentum (kg m/sec)
	Mass (kg)	Part I	Part II	Part I	Part II	Part I	Part II

Steel

Glass

Experimental Error:

Using the information calculated in the previous table, determine your experimental error by calculating the percent difference between the total momentum for Part I and the total momentum for Part II.

Total Momentum
(kg m/sec)

Part I

Part II

% difference

What impulse did the glass ball give to the steel ball during the collision in Part II?