1. Machines
Levers & Torque

2. Torque
The turning effect caused by a force on a rigid object around an axis or fulcrum.
Represented by T
Units: Newton metres (Nm)
Consider a textbook. Is it easier to open the book by pushing closer to the spine (fulcrum) or further away?
The further away the easier it is.

3. From this we can conclude that torque depends on two quantities:
The (perpendicular) force applied.
The distance away.
In other words:
Where:
T = Torque (Nm)
F = Force (N)
d= Distance (m)

4. Eg.1: Calculate the magnitude of the torque on a wrench if 100 N of force are applied 0.30m from the bolt.

5. Torque & Levers Two torques can be calculated for a lever:
Effort Torque (TE ):
Load Torque (TL):
Where:
F = Force (effort / load)
d= Arm length (effort / load)

6. Static Equilibrium & Levers
In order for a lever to be in static equilibrium (not moving) we use the law of levers:

7. Eg.2: What effort force is required to lift 45 kg using a first class lever with a load arm of 0.4m and an effort arm of 2m?
Eg.3: Supposing you can provide an effort force of 100N, what is the largest mass you can lift with a second class lever and an effort arm length of 1.2m and a load arm length of 0.25m?