Pasco Scientific ME-9429A, Instruction Manual And Experiment Manual

Page: 13 / 46

9
012-05035E Dynamics Cart Accessory Track Set
Experiment 2: Conservation of Momentum in Collisions
EQUIPMENT NEEDED:
– Dynamics Cart with Mass (ME-9430)
– Collision Cart (ME-9454)
– (2) Bumper magnet set (installed)
– Dynamics Cart Track
– Paper
Purpose
The purpose of this experiment is to qualitatively explore conservation of momentum for elastic and
inelastic collisions.
Theory
When two carts collide with each other, the total momentum
p = mv
of both carts is conserved
regardless of the type of collision. An elastic collision is one in which the two carts bounce off each
other with no loss of kinetic energy. In this experiment, magnetic bumpers are used to minimize the
energy losses due to friction during the collision. In reality, this “elastic” collision is slightly inelastic.
A completely inelastic collision is one in which the two carts hit and stick to each other. In this
experiment, this is accomplished with the hook-and-pile tabs on the end caps of the carts.
Procedure
➀
Level the track by setting a cart on the track to see which way it rolls. Adjust the leveling feet at the
end of the track to raise or lower that end until a cart placed at rest on the track will not move.
➁
Draw two diagrams (one for before the collision and one for after the collision) for each of the
following cases. In each diagram, show a velocity vector for each cart with a length that approxi-
mately represents the relative speed of the cart.
Part
I
: Elastic Collisions
A. Carts with Equal Mass
Orient the two carts so their magnetic bumpers are toward each other.
Case 1: Place one cart at rest in the middle of the track. Give the other cart an initial velocity toward the
cart at rest.
Case 2: Start the carts with one at each end of the track. Give each cart approximately the same velocity
toward each other.
Case 3: Start both carts at one end of the track. Give the first cart a slow velocity and the second cart a
faster velocity so that the second cart catches the first cart.
Leveling foot