P3

HideShow resource information

Speed

  • How far something goes.
  • measure speed we need the distance it went and time it took.
  • an average speed is, initial speed + final speed/2
  • Acceleration how quickly speed changes
1 of 7

graphs

  • distance-time graph, steeper slope=faster object moving
  • distance-time graph, speed=gradient
  • distance-time graph, curved line=object accelerating or decelerating.
  • speed-time graph, flat line= steady speed
  • speed-time graph, acceleration=gradient
  • speed-time graph, area under line=distance travelled
2 of 7

Force

  • velocity=speed including direction.
  • push car, smaller mass+bigger force=bigger acceleration
  • forces act in pairs- every action there is an equal and oppisite reaction
3 of 7

Stopping distance

  • made up of two parts, thinking and braking.
  • thinking, how far travelled whilst reacting, can be increased by drinking and tierdness.
  • braking, how far travelled whilst car breaking,increased by worn tyers, slippery or icey roads.
4 of 7

Kinetic Energy

  • Work, measure energy used.
  • Power, how quickly energy is used.
  • car stops, all work done by breaks=kinetic energy lost
  • car= more fuel used if bigger engine or drive uphill or have to stop-start your journey.
  • smaller fuel consumption in liters/100km further can drive on tank of petrol
  • kenetic energy linked to speed^2, double speed braking distance quadrouples.
  • crashes, kinetic energy in car=0
  •  energy cant be made or destroyed but wasted through heat and sound.
  • Rollercosters potentional gravitational energy at start= kinetic energy lost at end unless energy is lost.
5 of 7

Car saftey

  • modern cars designed to absorb the energy through seatbelts, crumple zones and air bags.
  • Car design aims to increase time for impact, reduces deceleration and force acting on you
  • primary safty features prevent crash such as ABS, traction control
  • secondary safty features, prevent with safty cage, crumple zone and paddle shift gears.
  • passive safty features, consentrate, electric windows, cruise control, paddle shift gears.
  • ABS=anti-locking braking system, controls wheel speed by computer stops skidding for shorter stopping distance.
6 of 7

Falling

  • Weight=force by gravity 10 newtons for every kilogram on earth.
  • All objects fall at same rate 10m/s^2
  • Terminal velocity= maximum speed falling object can go, where weight =air resistance 
  • reduce resistance by streamlining.
7 of 7

Comments

No comments have yet been made

Similar Physics resources:

See all Physics resources »See all P3 resources »