Moments
Moment – Turning Effect
The moment of a force is a measure of its ability to turn something – to provide a Torque
Moment (Nm) = Force (N) * Perpendicular Distance (m)
M = Fd
Always include a direction – clockwise or anticlockwise
Principle of moments
When a body is in equilibrium, the sum of the clockwise moments about any point is equal to the sum of the anti-clockwise moments about the same point
Centre of Mass (CoM)
Aka. the centre of gravity
Determined by the object's distribution of mass
The point about which all the mass of an object can be considered to act
Can be outside an object depending on its shape and mass distribution
*Providing an object is in equilibrium, the CoM will always be above/below the fulcrum
Finding CoM
Consider symmetry
Hang it from multiple positions – find the CoM at the intersect
Stability
3 types:
Stable – slight displacement results in CoM increasing in height
Unstable – slight displacement results in CoM decreasing in height
Neutral – slight displacement results in CoM remaining at the same height