AP Physics: Momentum and Collisions

big 5

Definition of Momentum

Mass in motion or the difficult to stop a moving object (Momentum=P) Measured in Joules/ Newtons per Meter

Force vs. Time Graph

The area under the curve represents the impulse, which is equal to the change in momentum.

Momentum vs Time Graph

A graph that shows how momentum changes over time, with the slope representing the force applied.

Collisions (Closed Systems)

mass, energy, and momentum are conserved. Therefore they can be calculated through Pi=Pf

As momentum increases

velocity increases (direct)

Inelastic collisions

Objects collide and stick together, KE is NOT conserved! (turns into heat, light, sound, PE.

Elastic Collisions

KE is NOT conserved, Pi=Pf and objects do NOT stick together.(equation is normal)

Equation for inelastic collisions

m1(v1i)+m2(v2i)=(m1+m2)vfsys

Two Dimensional collisions

calculate both dimensions (x-y) and find hypotenuse using pythag to find momentum of system.

Equation for Explosion

(m1+m2)visys=m1v1f+m2v2f (vi system ALMOST always zero meaning that m1v1f+m2v2f=0 normally)

Explosion

KE is usually not conserved and usually increases in the system (acceleration comes from outside factor) *newtons third law