Momentum Energy Work And Power Flashcards
What factors affect the thinking distance
Reaction time
How fast your going
What is thinking distance
the distance the car travels in the time between the driver noticing the hazard and applying the brakes
What is braking distance
The distance the car travels during its deceleration whilst the brakes are being applied
What factors affect braking distance
How fast you’re going
The mass of the vehicle
How good the brakes are
How good the tyres are
Momentum =
Mass x velocity
Force =
Change in momentum/ time
What protective features do cars have
Crumple zones crumple on impact increasing the time taken for the car to stop
Seat belts stretch slightly increasing the time for the wearer to stop this reduces the forces acting in the chest
Air bags slow the person down more gradually
Work done =
Force x distance moved in the direction of the force
Power =
work done / time taken
What is power measured in
Watts or joules per second
Kinetic energy =
1/2 x Mass x velocity
Gravitational potential energy=
Mass x gravitational field strength x height
What is the principle of conservation of energy
Energy can never be created or destroyed only transferred from one form to another
What happens when an object falls
Gravitational potential energy is converted to Kinetic energy
Kinetic energy gained = gravitational potential energy lost
