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Chapter 3, 4
Revise Force and Motion
|Speed is how long it take to get from one point to another.
|How can you measure speed?
|Speed is measured in Distance divided by Time. S=D/T
|What are the units of speed?
|Meters per second, Kilometers per hour.
|Velocity is speed in a certain direction.
|Acceleration is the rate of change of velocity (or speed).
|How can you measure acceleration?
|Acceleration = Change in Velocity (final velocity - initial velocity) divided by Time taken.
|What are the units of acceleration?
|Meters per second squared. M/s2.
|What is a force?
|a force is something that causes an object to change velocity or acceleration.
|What is Friction?
|Friction is a force which opposes motion between two objects.
|What are advantages and disadvantages of Friction?
|They allow us to move by pushing out feet against the ground when we walk. It can cause objects to grind and wear out.
|What can we use to reduce friction?
|Oil lubricants, Ball bearings, streamlining to reduce air/water friction.