More Machines and Graphs

Machines

A machine is anything that can help us to work with forces. Most machines help by allowing us to use a smaller force to move an object. Levers are simple machines. Another type of simple machine is a ramp.

Pulleys and ramps

Pulleys: When you double the distance, you reduce the force

Ramps: Straight up is a short distance and a big force but along a wrong is a longer distance bu smaller force

Work Done

Energy transferred by a force when it makes something move is called work done

Formula for work done

Work done= Force (N) times by Distance moved in direction of force (m)

Explanation for 3a

When we calculate work done against gravity, only the verticle eight matters because gravity acts vertically.

The ramp does not change how much energy is needed, it only changes how it is supplied.

However for working out the force, the pushing force acts against tthe ramp, over the full 3m so this measurment is used.

Examples of Vector and Scalar

Vector:
Velocity
Displacement
Current
Momentum
Acceleration
Force

Scalar:
Distance
Mass
Speed
Time
Energy
Power

Speed vs Velocity

Speed is how fast you are travelling but velocity is speed in a given direction.
Speed: 20m/s Velocity: 20m/s East