momentum Flashcards
what does the principle of conservation of momentum state
total momentum before a collision = total momentum after a collision
momentum equation
mass x velocity
the momentum of n object depends on what
its direction of travel (because velocity is a vector)
when is momentum positive
if its moving forwards
when is momentum negative
when object moves backwards
The momentum of an object will change if: (3)
it’s velocity increases or decreases (acceleration)
it’s direction changes (acceleration)
it’s mass changes
The shorter the time over which momentum changes, the bigger or smaller the force ?
Bigger
time and force are
inversely proportional
the impulse of a collision is equal to
the change in momentum
the change in momentum equation
momentum after - momentum before
impulse of a collision equation
force x change in time
the higher the impact force the __ the change in momentum
bigger
how does an airbag work
- it absorbs energy on impact by changing shape
- to increase impact time of force
- meaning it increases the time it takes for the vehicle to change momentum, and come to a rest
- this reduces the force, and injury
3 saftey features of a car
crumple zone
seatbelt
airbag
all safety features do what
increase impact time and decrease force
what does netwons third law show
all forces arise in pairs
newtons third law force must be the same in (2) and opposite in (2)
type of force
magnitude
direction
act on different objects
force (rate of change in momentum =)
momentum at end- momentum at start / time
