MOMENTUM AND COLLISIONS NAME _________________________
PARTNER
_________________________
DATE
DUE _________________
DATE _________________________
PURPOSE: In
this lab, you will measure the effects of a collision on two objects.
EQUIPMENT: air
track photogates (2) Velcro strips air track gliders (2 small gold if possible)
air supply (5" x 8" note card if you are
using the large red gliders)
PROCEDURE:
I. ELASTIC COLLISIONS
1. Weigh each air glider and RECORD
in the Data Table. MAKE SURE THEY ARE
THE SAME SIZE
2. Assemble the air track and photogates as
shown in "Figure #1". LEVEL
THE AIR TRACK (Hint: the closer
together the photogates are together the less momentum you’ll loose while
traveling to the next photogate
after the collision. The less momentum
lost, the smaller your %Difference will be.)
E MAKE
SURE THE DISTANCE BETWEEN THE PHOTOGATE LIGHT BEAM AND THE END OF
THE AIR TRACK IS GREATER THAN THE LENGTH OF THE GLIDER.
3. Adjust the height of each photogate so the
light beam is the same height as the fin on the gliders.
4. Measure the lengths of each glider fin and RECORD
in the Data Table 1. (You can use the yellow ruler on the side of the air track.)
5. Turn on the air supply to the air tracks
and position the gliders as shown in "Figure #1" (on the last
page).
6. Reset the photogate timers to
"0".
7. Give glider #1 a SLIGHT push
so that it goes through photogate #1 and collides with glider #2.
8. After glider #2 goes through
photogate #2, one of the lab partners has to catch it so that it DOES NOT
BOUNCE
BACK THROUGH THE PHOTOGATE.
9. RECORD both photogate times in the
Data Table 1.
DATA TABLE I: Elastic Collisions
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|
GLIDER |
GLIDER MASS (gm) |
GLIDER LENGTH (cm) |
PHOTOGATE TIMER (sec) |
|
1 |
|
|
|
|
2 |
|
|
|
II. INELASTIC COLLISION
10. Attach Velcro strips to the spring bumpers of
each glider where they come in contact with each other.
11. If you are using the large red gliders: Attach
a 5" x 8" note card (cut lengthwise) to the fin of glider #2
as shown in Figure #2. Raise the photogate #2 high enough so
that the light beam only hits the note card. Measure the length of the
note card and record in Data Table 2 in the box for Glider length 1+2.
If you are using the small gold
gliders: The glider length of 1+2 will be the lengths of the 2
gliders added together since both pass through the
photogate.
12. Repeat Steps #7 - #9 above and RECORD
the times in the Data Table 2 for Inelastic Collisions.
DATA TABLE II: Inelastic Collisions
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|
GLIDER |
GLIDER MASS (gm) |
GLIDER LENGTH (cm) |
PHOTOGATE TIMER (sec) |
|
1 |
|
|
|
|
1+2 |
|
|
|
III.
MOMENTUM LOST IN A COLLISION:
1. Remove one of the gliders (the one with the
note card if you have the red glider) from the air track.
2. Turn on the air supply and give the
remaining glider a SLIGHT push through the photogates.
3. As the glider passes through the photogate
#2, QUICKLY RESET THE TIME ON THE TIMER.
4. After the glider bounces off of the end of
the air track, let it go through photogate #2, but stop the glider before it passes back through photogate #1.
5. RECORD the time on the timer for photogate
#1.
6. RECORD the time on the timer for photogate
#2.
7.
Either remove the rubber band or
replace the rubber band (which ever you did not do) on the end of the
air track and repeat Steps
#2-#6.
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DATA TABLE III: Momentum Lost in a Collision |
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|
TRIAL N0. |
TYPE
of SPRING |
GLIDER MASS (gm) |
PHOTOGATE #1 (sec) |
PHOTOGATE #2 (sec) |
|
1 |
RUBBER BAND |
|
|
|
|
2 |
STEEL SPRING |
|
|
|
CALCULATIONS: SHOW ALL YOUR CALCULATIONS ON A SEPARATE PAGE
PUT YOUR RESULTS IN THE CALCULATION
TABLES
NOTE: You may convert from centimeters and grams to meters and kilograms if you wish for your momentum units to be kg*m/s. Or you can leave your measurements in centimeters and grams and have your momentum units in g*cm/s. Either is fine AS LONG AS YOU MAKE YOUR CHOICE OBVIOUS AND CONSISTENT.
Formula
#1
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ELASTIC COLLISIONS
1. Calculate the VELOCITY of each glider using
Formula #1 at the right, where:
"d" is the length of the glider fin,
and
"t" is the time for the glider fin to pass
through the photogate.
Formula
#2
2. Calculate the MOMENTUM of each glider for
the Elastic Collisions using
Formula #2 at the right where:
"m" is mass, and
Formula
#3
"v" is velocity of the glider (found
in Calculation #1).
