# Momentum lab report

Topics: Momentum, Collision, Elastic collision Pages: 6 (1198 words) Published: December 5, 2013

Momentum Conservation
INTRODUCTION:
This lab shows in detail how collisions work in an almost ideal situation. This lab was set up to test final velocities of carts involved in a series of collisions. This process helps explain how velocities are affected by mass in both elastic and inelastic collisions. There are five scenarios that are to be evaluated. In scenario one it is expected that when carts of equal mass are collided in an elastic collision, one moving (cart one) and one stationary (cart two), both carts will move in opposite directions with half of the original velocity of the original moving cart. In scenario two cart one elastically collides with cart two which is one third of cart one’s mass. It is expected that cart two will be moving at nearly the original speed of cart one and that cart one will barely slow down. In scenario three cart one elastically collides with cart two, which is now three times the mass of cart one. It is expected that cart one will be propelled in the opposite direction while cart two will hardly move. In the fourth scenario cart one collides inelasticlly with cart two, which is two times the mass of cart one with cart two originally at rest. It is expected that both carts will combine and move very slowly in the direction of cart one. In the final scenario both carts collide inellasticly and are moving at the same initial velocity and have equal masses. It is expected that in this final scenario both carts will stop.

MATERIALS:
Two carts of 500g are placed on a level meter long track. At each side of the track there are motion sensors which are hooked up to a computer to capture data pertaining to the velocity and relative positions of the two carts. To increase the weight of the carts, one or two 500g blocks are placed on top of the carts to double or triple their mass. PROCEDURE:

At the beginning of each run the cart that is to be moving (in scenario five both carts) is placed at the end of the track. The cart that is to be collided into is placed in the center of the track to help give the longest distance possible from the sensor for the longest period of data collection. One student manned the computer to turn on the sensor to collect the data for each run. Another student, once the clicking of the sensor started indicating that data capturing has started, gives the cart that is to be moved a push. The carts are allowed to collide and once motion stops the sensor is turned off.

Scenario 1
Mass (grams)
Initial Velocity (m/s)
Final Velocity (m/s)
Initial Momentum
(Kg m/s) or (N)
Final Momentum
(Kg m/s) or (N)
%Error
Cart 1
500
0.7
0
0.35
0
NA*
Cart 2
500
0
0.7
0
0.35
0%**
Scenario 2

Cart 1
1500
0.7
0.35
1.05
0.525
38%
Cart 2
500
0
1.05
0
0.525
0%**
Scenario 3

Cart 1
500
0.7
-0.35
0.35
-0.175
57%
Cart 2
1500
0
0.35
0
0.525
19%
Scenario 4

Cart 1
500
0.5
0.167
0.25
0.2505
40%
Cart 2
1000
0
0.167
0
0.2505
40%
Scenario 5

Cart 1
500
0.2
0
0.1
0
0%**
Cart 2
500
-0.2
0
-0.1
0
0%**
The positive direction is the initial direction of cart one. *value is equal to (0.2)/0 which does not exist
**value is equal (#/#)*100 which would give 100% error for the situation when the calculated momentum is equal to the measured momentum (which is 0% error) (where # in any number over itself)

For all scenarios Velocity one on the graph corresponds to velocity of cart two Scenario 1:

Scenario 2:

Scenario 3:

Scenario 4:

Scenario 5:

ANALYSIS:
The final velocity for cart one in scenarios one-three was calculated by the formula: [(M1-M2)/(M1+M2)]Vi1=Vf1
The final velocity for cart two in scenarios one-three was calculated by the formula: [(2M1)/(M1+M2)]Vi1=Vf2
The final velocity for both cart one and cart two in scenarios four-five was calculated by the formula: M1Vi1+M2Vi2= M1Vf+M2Vf
Momentum was calculated...