The Cart and The
Brick
Part A
A GIF Animation
Collisions between objects are governed by laws of momentum and
energy. When a collision occurs in an isolated system, the total
momentum of the system of objects is conserved. Provided that there
are no net external forces acting upon the objects, the momentum of
all objects before the collision equals the momentum of all objects
after the collision. If there are only two objects involved in the
collision, then the momentum lost by one object equals the momentum
gained by the other object.
The animation below portrays the collision between a 3.0-kg
loaded cart and a 2-kg dropped brick. It will be assumed that there
are no net external forces acting upon the two objects involved in
the collision. The only net force acting upon the two objects (loaded
cart and dropped brick) are internal forces - the force of friction
between the loaded cart and the droped brick. The before- and
after-collision velocities and momentum are shown in the data tables.
In the collision between the loaded cart and the dropped brick,
total system momentum is conserved. Before the collision, the
momentum of the loaded cart is 150 kg*cm/s and the momentum of the
dropped brick is 0 kg*cm/s; the total system momentum is 150 kg*cm/s.
After the collision, the momentum of the loaded cart is 90.0 kg*cm/s
and the momentum of the dropped brick is 60.0 kg*cm/s; the total
system momentum is 150 kg*cm/s. The momentum of the loaded
cart-dropped brick system is conserved. The momentum lost by the
loaded cart (60 kg*cm/s) is gained by the dropped brick.
For more information on physical descriptions of motion,
visit
The
Physics Classroom. Specific information is available there on the
following topics:
This page was created by
Tom
Henderson of
Glenbrook South
High School.
Comments and suggestions can be sent by e-mail to
Tom
Henderson.
This page last updated on 6/2/97.