Chapter 4 Moments - Year 2 Flashcards
What is the formula for moments of an xN force around P?
Force X perpendicular distance
What do you often forget to do when answering questions about simple moments questions?
You need to state anticlockwise or clockwise
Wherever there is a pivot point what is there also?
A reaction force at that pivot
If you have a system that is in equilibrium what 2 things do you know?
The moments around it must be equal (anticlockwise and clockwise)
Upwards forces and downwards must be equal
What does uniform rod mean?
The weight is in the middle
What is a useful to keep in mind when using moments?
If you calculate the moment around a pivot that reaction force will disapear
If you are told that there is a non uniform rod of mass m what do you always need to do?
Put in the weight force somewhere random on the rod (normally near the centre) and label a distance x
What do you know is true if a rigid body is about to tilt around a pivot A?
The reaction force at any other pivot will be 0
What is the main method for questions about tipping?
1) You either assume that the point is on the point of tipping then work out the distance x that would cause that of a specific force
2) Labelling different lengths x then using simulations equations
