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GCSE C21 P4
GCSE C21 P4 Explaining Motion revision
| Question | Answer |
|---|---|
| Instantaneous Speed = | Distance / Time (small distance and short time) |
| Average Speed = | Distance / Time (journey distance and journey time) |
| Speed from a distance time graph… | find the gradient of the graph = vertical / horizontal |
| In a distance time graph horizontal means | the object is stopped |
| In a distance time graph the steeper the slope... | the faster the object is going |
| In a distance time graph the downhill section means | the object is moving backwards / towards you |
| Velocity is speed and | direction |
| In a velocity time graph gradient represents.... | acceleration |
| In a velocity time graph horizontal means | constant speed |
| In a velocity time graph the steeper the slope... | the greater the acceleration |
| In a velocity time graph uphill sections indicate... | Acceleration or speeding up (positive acceleration) |
| In a velocity time graph downhill sections indicate.. | deceleration or slowing down (negative acceleration) |
| Newton’s third law: if you push against a wall the wall... | pushes back on you |
| Resultant force is... | the overall force acting on an object. |
| Momentum = | mass x velocity |
| Change in momentum = | FORCE x TIME (resultant FORCE x TIME for which the force acts) |
| Change in energy is the same as | Work done |
| Work Done = | Force x Distance |
| Kinetic Energy | 1/2 mass x velocity squared |
| The formula for change in gravitational potential energy is | Weight x change in height |
| Falling objects convert gravitational potential energy into | Kinetic energy |
| Units for kinetic energy | J or joules |
| Units for potential energy | J or joules |
| Units for mass | kg or kilograms |
| Units for speed (standard scientific units) | m/s or metres per second |
| Units for momentum | kg m/s or kilogram metres per second |
| Units for work done | J or joules |
| Units for weight | N or newtons (weight is a force) |
| Units for force | N or newtons |