Sports Science HL B.1.4 Levers

Fulcrum Structure

A fulcrum is made of a rod, a fulcrum, a load force, and an effort force.

Force

A push or pull that causes an object to start or stop moving. This is often in a linear path.

Torque

A rotational force, or a tendency to cause rotation about a fixed point. Calculated by multiplying a force by the distance from the fulcrum that force is applied.

Mechanical Advantage

- The length from fulcrum to you is called the effort arm,
- The length from the fulcrum to the object you are lifting is the load arm,
- If the effort arm is very large, it will cause a very high torque, this means you will be able to lift a very heavy object with ease.

First Class Lever

- Fulcrum in the middle
- Can have any range of MA
- Ex. See Saw, skull on head

Second Class Lever

- Load in the middle
- MA always above 1
- Ex. Wheel barrow, plantar flexion / ankle movement when jumping

Third Class Lever

- Effort in the middle
- MA always below 1
- Ex. Salad tongs, bicep curl