Point masses

Definition

Point masses are idealized objects that have mass but occupy no volume. They are used in physics to simplify problems involving motion and collisions.

5 Must Know Facts For Your Next Test

1. Point masses allow for simplified calculations in two-dimensional collisions by focusing only on mass and velocity.
2. During a collision, the total linear momentum of point masses is conserved if no external forces act on the system.
3. The equations governing the conservation of momentum can be separated into components: $m_1v_{1x} + m_2v_{2x} = m_1u_{1x} + m_2u_{2x}$ and $m_1v_{1y} + m_2v_{2y} = m_1u_{1y} + m_2u_{2y}$.
4. Elastic collisions between point masses conserve both kinetic energy and momentum, while inelastic collisions only conserve momentum.
5. In two-dimensional collisions, angles of deflection and final velocities can be determined using trigonometric relationships.

Review Questions

Related terms

Linear Momentum:

The product of an object's mass and its velocity, represented as $\mathbf{p} = m\mathbf{v}$.

Elastic Collision:

A type of collision where both kinetic energy and linear momentum are conserved.

Inelastic Collision:

A type of collision where only linear momentum is conserved, but some kinetic energy is transformed into other forms of energy.