Forces in equilibrium Flashcards
Displacement
Distance in a given direction
Scalar
A physical quantity with magnitude only
Vector
A physical quantity with both magnitude and direction
Velocity
Change of displacement per unit time
Force
Any interaction that can change the velocity of an object
Acceleration
Change of velocity per unit time
The moment of a force about a point
Force x perpendicular distance from the line of action of the force to the point
The principle of moments
For an object in equilibrium, the sum of the clockwise moments about any point = the sum of the anticlockwise moments about that point
Centre of mass of a body
The point through which a single force on the body has no turning effect
Couple
A pair of equal and opposite forces acting on a body but not along the same line
Torque of a couple
Force x perpendicular distance between the lines of action of the forces
Equilibrium
State of an object when at rest or in uniform motion
Free-body force diagram
A diagram of an object showing only the forces acting on the object
Weight
The force of gravity acting on an object
