Activity-10. : Momentum Conservation In 2-D Collisions
Activity-10. : Momentum Conservation In 2-D Collisions
Lab # Who Knows At This Point
Co-Authors: None Because We Have Been Abandoned
Activity-10. : Momentum Conservation In 2-D Collisions
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Activity-10. : Momentum Conservation In 2-D Collisions
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Purpose
The purpose of this lab was to verify that momentum was conserved in a collision
between two air pucks and determine what type of collision occurred (elastic or inelastic).
Equipment
The only things needed for this lab are the program Logger Pro and a pen, paper, a
computer, and a calculator.
Procedure
First the video Activity-10. was inserted into Logger Pro and watched. Then points were
placed to track the position of the left puck before the collision, and after the collision, along
with the position of the right puck before and after the collision. This data was used to create
eight graphs: x velocity versus time for the right puck before the collision (Figure 1), y velocity
versus time for the right puck before the collision (Figure 2), x velocity versus time for the left
puck before the collision (Figure 3), y velocity versus time for the left puck before the collision
(Figure 4), x velocity versus time for the right puck after the collision (Figure 5), y velocity
versus time for the right puck after the collision (Figure 6), x velocity versus time for the left
puck after the collision (Figure 7), and y velocity versus time for the left puck after the collision
(Figure 8). These graphs were used to fill out Table 1, Table 2, Table 3 and Table 4.
Data
Activity-10. : Momentum Conservation In 2-D Collisions
Figure 1: X velocity versus time for the right puck before the collision
Figure 2: Y-velocity versus time for the right puck before the collision
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Activity-10. : Momentum Conservation In 2-D Collisions
Figure 3: X-velocity versus time for the left puck before the collision
Figure 4: Y-velocity versus time for the left puck before the collision
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Activity-10. : Momentum Conservation In 2-D Collisions
Figure 5: X-velocity versus time for the right puck after the collision
Figure 6: Y-velocity versus time for the right puck after the collision
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Activity-10. : Momentum Conservation In 2-D Collisions
Figure 7: X-velocity versus time for the left puck after the collison
Figure 8: Y-velocity versus time for the left puck after the collision
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Activity-10. : Momentum Conservation In 2-D Collisions
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Table 1
Table 2
Left Puck
Right Puck
Before
After
Before
After
VLix
0.3373
VLfx
-0.04981
VLiy
-0.1697
VLfy
-0.4415
VRix
0.06338
VRfx
-0.00038
PLix
0.101
PLfx
-0.015
VRiy
0.6319
VRfy
0.6117
PLiy
-0.051
PLfy
-0.132
PRix
0.019
PRfx
-1.14x10-4
VLi
0.378
VLf
0.444
PRiy
0.189
PRfy
0.183
VRi
0.635
VRf
0.612
Table 3
System
Before
After
Psysix
0.12
Psysfx
-0.015
Psysiy
0.138
Psysfy
0.051
Table 4
Kinetic Energy
Before
KEsysi
0.0818
After
KEsysf
0.0856
Conclusions
Activity-10. : Momentum Conservation In 2-D Collisions
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This experiment only confirmed that kinetic energy was conserved. For some reason, it did not
confirm that momentum was conserved. This was most likely due to errors with calculations or
with Logger Pro
Questions and Answers
1. Why does the location of the origin not matter in this activity?
Because we are using vectors so no matter the coordinate system the magnitude will
always be the same.
2. Are the x and y components of momentum for the system the same (to within
uncertainties) before and after the collision?
No they are not.
3. Does the data you have collected indicate that momentum was conserved in this
collision? Briefly explain your answer.
No, because before the collision the momentum of the system was 0.1829 and after the
collision the momentum was 0.0532. These are not the same.
4. Was the kinetic energy of the system the same (to within uncertainties) before and
after the collision?
Yes it was.
5. What type of collision—elastic or inelastic—was this? Explain your choice.
This was an elastic collision because kinetic energy was conserved. Momentum most
likely would have been conserved as well, but there seems to be errors in the calculations.