Moment Of A Force

Question 1

Moment of Force

Answer 1

Def: the moment of a force about a point is the product of the force & the perpendicular distance to the pivot

• Sometimes when a force acts on a body it may cause it to turn i.e. it has a turning effect
• the turning effect is known as the moment of a force
  -the moment of a force depends on
  • the force applied
  • the perpendicular distance of the pivot from the force

Question 2

Equation for Moment of a Force

Answer 2

Moment of a Force=
Force x perpendicular distance at a right angle
Torque= F x d
- Unit= Nm
N=F M=d

Question 3

The Moment of a Force is evidently a quantity & therefore must have:

Answer 3

•MAGNITUDE- given by the equation
•DIRECTION- described as either CLOCKWISE or ANTICLOCKWISE & is ALWAYS indicated on diagrams
(Direction is specifically clockwise or anticlockwise abt the pivot)

Question 4

Principle of Moments

Answer 4

“For a body in EQUILIBRIUM, the sum of the CLOCKWISE moments abt a point is EQUAL to the sum of the ANTICLOCKWISE moment abt the same point”

Question 5

Conditions necessary for Equilibrium

Answer 5

• The sum of the CLOCKWISE moment abt any point must be EQUAL to the sum of the ANTICLOCKWISE moment abt the same point i.e. the Principle of Moments
• The sum of the forces in any direction is EQUAL to the sum of the forces in the OPPOSITE direction