| Difference between scalar and vector quantities | Scalar quantities only have magnitude and no direction, whilst vectors have both |
| Examples of scalar quantities | Speed, distance, mass, temperature, time |
| Example of vectors quantities | Force, velocity, displacement, acceleration, momentum |
| Force definition | A push or a pull on an object caused by it interacting with something |
| Examples of contact forces | Friction, air resistance, tension in ropes |
| Examples of non-contact forces | Magnetic force, gravitational force, electrostatic force |
| Relationship between mass, weight and gravitational field strength | For a given gravitational field strength, the greater the mass of the object, the greater its weight |
| What is mass? | Quantity of matter in an object |
| What is weight? | The force acting on an object due to gravity |
| How to find the resultant force of forces acting in the same direction on a straight line | Add the forces together |
| How to find the resultant force of forces acting in opposite directions in a straight line | Subtract the forces |
| What is a free body diagram? | A diagram that shows all forces acting on an object |
| What happens if the resultant force is zero? | There is no change in direction or speed |
| What do vector diagrams illustrate? | Two forces acting on an object at right angles |
| How to calculate between joules and newton-metres | 1J = 1Nm |
| What causes a rise in temperature? | Work done against the frictional forces acting on an object |
| When is equilibrium reached? | If all of the forces acting on an object give a resultant force of zero |
| Give an example of a force used in stretching | Elastic force |
| Give an example of a force used in compressing | Compression force |
| Give an example of a force used in bending | Bending force |
| What is elastic deformation? | When an object is stretched by a force but once the force is no longer applied it resumes its natural shape and length |
| What is inelastic deformation? | When an object is stretched by a force but once the force is no longer applied it cannot resume its natural shape or length |
| Describe the relationship between the extension of an elastic object and the force applied | Extension is directly proportional to the force applied:
e [fish symbol] F |
| What is the limit of proportionality? | The point until the object's extension is no longer directly proportional to the force applied |
| What is the unit for pressure? | Pascals, Pa |
| What factors influence floating? | If the upthrust force is equal to the object's weight, if the object is less dense than the fluid and weighs less than its equivalent volume of fluid |
| What factors influence sinking? | If the upthrust is less than the object's weight, if the object is more dense than the fluid and weighs more than its equivalent volume of fluid |
| Difference between distance and displacement | Distance is scalar, displacement is vector |
| Difference between speed and velocity | Speed is scalar, velocity is vector |
| Describe motion in a circle | Constant speed, changing velocity |
| In a distance-time graph what does gradient equal? | Speed |
| What does a straight uphill section on a distance-time graph show? | Constant speed |
| What does a curve on a distance-time graph show? | Acceleration or deceleration |
| What does a straight horizontal line on a distance-time show? | No speed |
| With a tangent, how do you find the gradient? | Gradient = change in x / change in y |
| In a velocity-time graph what does gradient equal? | Acceleration |
| What does a straight uphill section on a velocity-time graph show? | Constant acceleration |
| What does a straight downhill section on a velocity-time graph show? | Constant deceleration |
| What does a curve on a velocity-time graph show? | Increasing acceleration |
| What does a straight horizontal line on a velocity-time graph show? | Steady speed |
| What is terminal velocity? | Highest velocity sustainable by an object as it falls through a fluid |
| How does an object reach terminal velocity? | When the forces acting upon the object [air resistance and weight] become balanced |
| What is Newton's First Law? | A resultant force is needed to make something start moving, speed up or slow down |
| What is Newton's Second Law? | Resultant force is directly proportional to acceleration |
| What is Newton's Third Law? | When two objects interact, the forces they exert on each other are equal and opposite |
| What is the Law of the Conservation of Momentum? | The momentum of a system is constant if no external forces are acting on it |
| What is the concept of rate of change of momentum? | The quantity of motion, the volume of matter moved and the velocity at which it travels at is multiplied |
| Explain safety features for momentum in collisions | Seatbelts- increases time taken for body's momentum to reach zero, so reduces forces
Air bags- increase time taken for head's momentum to reach zero, so reduces forces
Crumple zones- increase time taken to change momentum of the driver and passengers in a crash which reduces forces |
