Chapter 13: Moments Flashcards
What is a moment?
A moment is the turning effect of a force around a fixed point, called a pivot.
What equation is used to find a moment?
moment = force x perpendicular distance from pivot
What unit are moments measured in?
Newtonmetres
What is the centre of mass, aka the centre of gravity?
The point through which the entire weight of an object acts.
What is the principle of moments?
At equilibrium, the sum of the anti-clockwise moments is equal to the sum of the clockwise moments.
How do forces act at equilibrium with moment?
Total upward forces = total downward forces
What is the purpose of the counterweight on a crane?
To prevent the crane from toppling over, concrete blocks are suspended at the other end of the load arm. They act as a counterweight to create a moment that opposes the moment due to the load.
How do you find the centre of mass of an irregular object?
Suspend the lamina at different points. At each point, hang a plum line down the centre and draw a line. Where these lines meet is the centre of mass.
