Chapter 37-Moments And Centre Of Gravity Flashcards
What is the moment of a force?
A moment of a force is a measure of its turning effect.
Name two methods of increasing the turning effect of an object.
1) Increasing the size of the force itself.
2) Increasing the distance from the applied force to the fulcrum.
What is the equation of the moment of a force?
Moment of a force = force ✖️ perpendicular distance from the force to the fulcrum.
What are levers?
Levers are simple machines that allow us to move or turn things more easily.
What does the law of the lever state?
It states that that when a lever is balanced, the sum of the clockwise moments is equal to the sum of the anti-clockwise moments.
What is the centre of gravity of an object?
It is the point through which all the weight of the object appears to act.
When can an object be balanced?
It can be balanced if supported either at its centre of gravity or at a point vertically above or below its centre of gravity.
Where are the centres of gravity of equally shaped symmetrical objects?
At their centres.
Name two ways objects can be made stable.
1) Giving them a low centre of gravity.
2) Giving them a wide base.
When is a body in stable equilibrium?
If, when slightly moved or tilted, its centre of gravity rises.
When is a body in unstable equilibrium?
If, when slightly tilted or moved, its centre of gravity falls.
When is a body in neutral equilibrium?
If, when slightly moved or tilted, its centre of gravity neither rises nor falls.
When will a body topple?
It will topple if a vertical line through its centre of gravity falls outside its base.
