scalar
Quantities that have magnitude but not direction
Eg.speed,distance,mass etc
vector
-quantities with a magnitude (size) and a direction
equation for speed distance time
D
SxT
acceleration
The change in velocity in a certain amount of time
equations for acceleration
A=(v-u)/t
equation for gradient
Y
—-
X
what is Newton’s 1st law?
A force is needed to make something start moving, speed up or slow down
what is Newton’s 2nd law?
Acceleration is proportional to the resultant force
what is Newton’s 3rd law?
When two objects interact the forces they exert on each other are equal and opposite
explain distance time graphs
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explain velocity time graphs
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equation for momentum
P= m x V
Momentum=mass x velocity
equation for force
Force= change in momentum/time
centripetal force
- a force which is moving in a circle
- travelling at a constant speed
- the velocity is constantly changing
how to investigate motion
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stopping distance
The time it takes for something to stop eg. A car
It includes thinking distance and braking distance
reaction time
The time it takes for someone to react
Things that affect your reaction time include tiredness,alcohol, drugs and distractions
what are the factors that affect stopping distance?
•the condition of the brakes
worn or faulty
•the mass of the car
A full car won’t stop as quickly
•how much friction between tyres and the road
If the road is icy or wet
what are the factors that affect reaction time?
-
equation for energy in the car
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how to estimate the distances involved in stopping
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kinetic energy
Anything moving has energy in its kinetic energy store
chemical energy
Anything that can release energy by a chemical reaction
definition of gravitational potential energy
Anything in a gravitational field (ie.anything that can fall)
elastic potential energy
Anything stretched, like springs, rubber bands etc
equation for GPE
GPE= m x g x h
equation for KE
KE= 0.5 x mass x (speed)²
how can energy be transferred between stores
In 4 main ways: •mechanically •electrically •by heating •by radiation
equation for efficiency
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explain how to make the use of energy more efficient
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non-renewable energy
- will run out
- typically burnt to provide energy
Eg. Coal, oil and natural gas
renewable energy
- won’t run out
- better for the environment
- may be unreliable or not provide as much energy
Eg.biofuels, wind, solar, hydro-electricity, tides
give examples of non-renewable energy sources
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what affect does non-renewable energy sources have on the environment?
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Thermal energy
Any object- the hotter it is, the more energy it has in this store
Electrostatic energy
Eg. Two charges that attract or repel each other
Magnetic energy
Two magnets that attract or repel each other
Nuclear energy
Atomic nuclei release energy from this store in nuclear reactions
