changes in momentum

Cards (8)

What causes a change in momentum?
forces
When a non zero resultant force acts on a moving object - it's velocity changes - it's momentum also changes
How do you calculate force with momentum and time?
Force = Change in momentum/ Change in time
What is equal to the rate of change of momentum?
the force
A larger force means...
a faster change of momentum and so a greater acceleration
What safety features do cars have?
Crumple zones
Seatbelts
Airbags
How do these work?
CRUMPLE ZONES
Crumple on impact, increases time taken for the car to stop
SEAT BELTS
Stretch slightly, increases the time taken for the wearer to stop
AIR BAGS
Inflate before you hit the dashboard of a car. The compressing air inside it slows you down more gradually than if you had just hit the hard dashboard
How do bike helmets provide safety?
Contain a crushable layer of foam which helps to lengthen the time taken for your head to stop in a crashReduces impact on your brain
How do crash mats and cushioned playground flooring provide safety?
Increase the time taken for you to stop if you fall on themMade of soft, compressible materials