# P3 OCR Gateway Science GSCE Physics

My notes I made for my exam which I re-sited so these notes are quite detailed because I knew I had to do better (which I did :D ) but some may be brief because I could remember the section :) Hope it helps!!

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• Created by: Lucy :)
• Created on: 11-03-13 22:35

First 225 words of the document:

Speed and Distance
Distance = Speed x Time
Average Speed =
Distance = Average Speed x Time = xt
^ flat sections = stopped
^ negative gradient = changed direction ­ going back home e.g.
^ curves = acceleration/de
Forces
GRAVITY or WEIGHT ­ always acting straight downwards
REACTION FORCE ­ from a surface, usually straight upwards
THRUST or PUSH or PULL ­ due to engine or rocket speeding something up
DRAG or AIR RESISTANCE or FRICTION which is slowing the thing down
LIFT due to an aeroplane wing
TENSION in a rope for cable
Stationary object = all forces in balance
Steady horizontal speed = all forces are in balance- unbalanced = acceleration
Steady vertical speed = all forces in balance
Horizontal acceleration = Unbalanced forces
Vertical acceleration = Unbalanced forces
Friction Forces + Terminal Speed
3 main ways: friction between solid surfaces which are gripping (static friction)
^ friction between solid surfaces which are sliding past each other
^ resistance or `drag' from fluids (liquids or gases, e.g. air)
FRICTION ALWAYS INCREASES AS THE SPEED INCREASES
Terminal speed = forces are balanced ­ maximum speed
^ depends on drag
Forces + Acceleration
Resultant force = overall unbalanced force
Force = mass x acceleration
Stopping Distance = thinking distance + braking distance

## Other pages in this set

### Page 2

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Thinking distance = the distance the car travels in the time between the driver noticing the
hazard + applying the brakes
Affected by 2: how FAST you're going + DOPEYNESS - tiredness, drugs, alcohol, distractions,
lack of concentration + careless attitude
Braking distance = the distance taken to stop once the brakes have been applied
Affected by 4: how FAST you're going, how HEAVILY LOADED the vehicle is, how good your
BRAKES are + how good the GRIP is - depends on 3 things: Road…read more

### Page 3

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Kinetic Energy gained = Gravitational Potential Energy lost
½ x m x v2 = mgh
2
h = v / 2g
Power = measure of how quickly work is being done
powerful machine = transfers a lot of energy in a short space of time NOT strong force
Power =
^ W (watts) or J/s (Joules per second)
Power = Force x Speed
Fuel Consumption + Emissions
Larger more powerful engine = more energy transfer from its fuel every second = usually