Moment of force

Question 1

Define Moment (vector)

Answer 1

It’s the product of the force and the perpendicular distance from the line of action of the force to the pivot.

Question 2

SI unit of Moment

Answer 2

Nm

Question 3

Formula of Moment

Answer 3

Moment = Force x Perpendicular distance from line of action of force to the pivot

Question 4

State the Principle of Moment

Answer 4

When an object is in equilibrium, the sum of clockwise moments about any pivot is equal to the sum of anticlockwise moments about the same pivot.

Question 5

Define Centre of Gravity

Answer 5

It is the point through which the entire weight of the object appears to act.

Question 6

Define Stability

Answer 6

It’s the measure of a body’s ability to maintain its original position

Question 7

State the 2 conditions to make a body more stable

Answer 7

1. Lowering its center of gravity

2. Increasing the area of its base

Question 8

What are the 3 states of equilibrium?

Answer 8

1. Stable equilibrium (There is a tilt but the object can return to rest).
2. Unstable equilibrium (The tilt of the object causes it to fall).
3. Neutral equilibrium (The object is already at rest).

Question 9

Why would an “unstable” object fall?

Answer 9

When the object has an unstable equilibrium, the line of action of the object’s centerof gravity falls outside the base area of the object. This produces a (direction) moment that causes the object to topple over.