Chapter 7: Introduction to Mechanics Flashcards
What is a scalar and what are some examples?
A quantity that only has magnitude, eg length, mass, temperature
What is a vector quantity and what are some examples?
A quantity with both magnitude and direction, eg velocity, displacement, acceleration
What is a resultant vector (vector sum)?
The vector that results from adding two or more vectors in a vector sum (eg resultant force)
What is a moment?
Force x perpendicular distance from the pivot to line of action of the force
What is a pivot?
The point about which an object rotates
What is the principle of moments?
When a body is in equilibrium, the total anticlockwise moment is equal to the total clockwise moment acting about a point
When is an object in equilibrium?
When the resultant force = 0 and the sum of turning moments = 0
What is the centre of mass?
The point in a body at which the mass appears to be concentrated
What is a couple?
A pair of forces that cause rotation but no translational movement.
They are equal, opposite, parallel, NOT along same line of action.
