Conservation of Momentum and Energy

(Institution)
(Name)
(Course)
(Unit)
(Unit Code)
Experiment: Momentum, Energy, and Collisions (Motion Detector)
(Professor’s Name)
(Date)

INTRODUCTION
Momentum and energy conservation can be described in terms of collisions of two carts a tracks.
Momentum conservation occurs when there is no net external force experience by the system of
the two carts while energy is only conserved when certain types of forces are exerted between
the carts. Momentum is expressed as a product of mass of the object and it velocity (Raymond
A. Serway).
Momentum=velocity∗mass
The types of collision can be classified in terms of kinetic energy; the main classification types
are elastic (kinetic energy is conserved), inelastic (kinetic energy is lost) or completely inelastic
(the object stick together after collision). Super-elastic collision condition occurs when kinetic
energy is gained. kinetic energy (KE) is expressed as product of mass and squared velocity
(Westerterp).
KE= 1
2∗mass∗Velocity2
OBJECTIVES
 To observe collisions between two carts, testing for the conservation of momentum.
 To measure the energy changes during different types of collisions.
 To classify collisions as elastic, inelastic, or completely inelastic.
MATERIALS
Computer
Vernier computer interface
Logger Pro
Two Vernier Motion Detectors
Vernier Dynamics Track
Two Vernier Dynamics Carts with magnetic and hook-and-pile strip bumpers
PRELIMINARY QUESTIONS
1. After collision ball 1 will remain in stationary position while ball 2 will move away at a
velocity that ball 1 was moving before colliding it.
2. .

3. Yes, kinetic energy and momentum are conserved, the ratio of both after and before
collision is 1:1.
PROCEDURE
1. The carts with the hook-and-pile pads were set up facing each other and the masses of the
carts measured and recorded in table as cart 1 and cart 2.
2. Dynamic track was set up in a horizontal position and tested by releasing a cart from rest
position while ensuring that the cart won’t move.
3. Motion detectors were placed at each end of the track while allowing a minimum distance
of 0.15m between the detector and the cart. The motion detectors were then connected to
the digital ports of the interface and the motion detectors sensitivity switched to track.
4. Cart 2 was positioned at rest in the middle of the track and cart 1 was released rolling
towards cart 2 with the hook-and-pile pads toward one another. The carts collide, stick
and roll together.
5. Opened file “18 Momentum Energy Coll” from the Physics with Vernier folder.
6. The collect button was clicked to collect data. The collision was then repeated while
using the position graphs to verify that motion detectors can track each cart through the
entire range of motion.
7. The two carts were placed at rest in the middle of the track with their hook-and-pile
bumpers towards each other and in contact. Hands were kept clear of the carts, clicked
the zero button and selected both sensors and clicked okay. The zeroing was then verified
by clicking the collect button and allowing the still-linked carts to roll slowly across the
track.
DATA TABLES