Summarizing Linear Momentum and Force

Summary

• Linear momentum (momentum for brevity) is defined as the product of a system’s mass multiplied by its velocity.
• In symbols, linear momentum \(\mathbf{p}\) is defined to be
  \(\mathbf{p}=m\mathbf{v},\)
  where \(m\) is the mass of the system and \(\mathbf{v}\) is its velocity.
• The SI unit for momentum is \(\text{kg}·\text{m/s}\).
• Newton’s second law of motion in terms of momentum states that the net external force equals the change in momentum of a system divided by the time over which it changes.
• In symbols, Newton’s second law of motion is defined to be
  \({\mathbf{F}}_{\text{net}}=\cfrac{\Delta \mathbf{p}}{\Delta t}\text{,}\)
  \({\mathbf{F}}_{\text{net}}\) is the net external force, \(\Delta \mathbf{p}\) is the change in momentum, and \(\Delta t\) is the change time.

Glossary

linear momentum

the product of mass and velocity

second law of motion

physical law that states that the net external force equals the change in momentum of a system divided by the time over which it changes