Momentum


Linear Momentum
Momentum is defined as p=mv (momentum = mass x velocity)
It is a vector, the sign/direction is important, unlike energy
A change in momentum is an impulse which is defined as F∆t=∆p (Force x time elapsed = impulse(change in momentum))
Momentum is conserved in all collisions
Types of collisions:
  • Elastic->kinetic energy is conserved
  • Inelastic-> kinetic energy not conserved -> objects stick together
No is perfectly either one, always somewhere in between
Easy formula for a perfectly elastic collision -> -(va-vb=v'b+v'a)
Interacts with Kinematics (1D Kinematics and 2D Kinematics)

Sample problem
external image 195_ch8_Momentum2.jpg
Follows p=p' (no external impulse to the system)
external image u4l2e5.gif

More help on
http://www.course-notes.org/Physics/Physics_Overview/Energy_and_Moment
um/Momentum

Center of Mass
The one point that moves in the same path that a particle would move had it of been subjected to the same force
Position relative to an origin x=(maxa + mbxb)/(ma+mb)



external image bat.gif





Angular Moment
Ben's rotational momentum part Rotation