The Cart and The
Brick
Part B
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 1.0-kg 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 (the cart
and the dropped brick) are internal forces - the force of friction
between the cart and the droped brick. The before- and
after-collision velocities and momentum are shown in the data tables.
In the collision between the cart and the dropped brick, total
system momentum is conserved. Before the collision, the momentum of
the cart is 60 kg*cm/s and the momentum of the dropped brick is 0
kg*cm/s; the total system momentum is 60 kg*cm/s. After the
collision, the momentum of the cart is 20.0 kg*cm/s and the momentum
of the dropped brick is 40.0 kg*cm/s; the total system momentum is 60
kg*cm/s. The momentum of the loaded cart-dropped brick system is
conserved. The momentum lost by the loaded cart (40 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 6/30/97.