Chapter 7: "Linear Momentum and Collisions"

ΣKEi=ΣKEf (use 1/2mv^2 for each object in the system)

Formula for conservation of internal kinetic energy (works for elastic collisions):

Σp=Σp'

Formula for conservation of momentum (works for all isolated systems):

Δp=FΔt

Formula for linear impulse as seen on the AP Physics 1 Equation Sheet:

p=mv

Formula for linear momentum as seen on the AP Physics 1 Equation Sheet:

x=m1x1+m2x2+.../m1+m2+...

Formula for the center of mass:

velocity

If a collision occurs in 2 dimensions, break the ___________ vectors into their compenents and solve for each dimension.

impulse

In a force vs. time graph, the area under the curve is the __________.

impulse, Δp

The average net external force times the time it acts; equal to the change in momentum.

center of mass

The average position of all the parts of the system, weighted according to their masses

change in momentum

The difference between the final and initial momentum; the mass times the change in velocity.

F=Δp/t

The formula for force in terms of impulse:

inelastic collision

A collision in which internal kinetic energy is not conserved. However, momentum is still conserved.

perfectly inelastic collision

A collision in which the colliding objects stick together.

elastic collision

A collision that conserves internal kinetic energy in addition to momentum.

isolated system

A system in which the net external force is zero. Only this type of system experiences the conservation of momentum.

constant, average, impulse

Although applied forces aren't usually __________, the __________ force applied over time works just as well when calculating ____________.

linear momentum, p

The product of mass and velocity.

internal kinetic energy

The sum of the kinetic energies of the objects in a system.

'

The symbol used to denote that this is the momentum of an object after a collision:

kg×m/s

The units for impulse:

kg×m/s

The units for momentum:

Δp

The variable used for impulse:

p

The variable used for momentum:

collision

The Δt in the formula for impulse is the length of time over which the __________ occurs, not the whole time.

conservation of momentum principle

When the net external force is zero, the total momentum of the system is conserved or constant.