Physics revision further-Turning forces
- It is the effect of a turning force
- To increase the moment
- Increase the size of the force
- Increase the distance between the point of force exertion and the pivot.
- The weight being moved is called the load
- The force being applied is called the effort
- Moment is worked out using the equation
- Moment = force x distance form force to pivot.
(Newton metre= Newtons x metres)
Centre of mass
- The COM is the point were all weight of an object acts from
- It is the point were all an objects mass may be thought to concentrate.
- An suspended object will come to rest with it’s COM directly below it’s point of suspension.
- When it is still this is called equilibrium.
- To find the COM of a symmetrical object you just find were the lines cross.
Moments in balance
- For an object to be balanced and stationary then the force of the clockwise and anticlockwise moments must be equal.
- A good example is a see-saw
· The base is the width of the bottom of the object
· An object will fall over when it’s COM acts outside it’s base
- A good way to visulise the COM acting is to imagaine a line between it and the centre of the earth.
- So when that line falls outside the base the object will fall over
- Examples of objects and basses
- Busses have to be tested to make sure they will not fall over.
- Tractors have wide bases so they can travel over bumpy land
- High chairs have to have a wide base so wiggly children will not fall out.
- For an object moving a circle…