5.5 - Turning Forces

Question 1

What is the turning effect of a force called?

Answer 1

Its moment

Question 2

What does the moment of a force depend on?

Answer 2

The size of the force and the perpendicular distance of its line of action from the axis of rotation

Question 3

What is the equation for calculating a moment?

Answer 3

Moment = Force * Distance

Question 4

What is the unit of a moment?

Answer 4

N m

Question 5

Does this unit fact mean it is the same as the joule?

Answer 5

No

Question 6

Why?

Answer 6

Because it has vector properties, and so can act in either the clockwise or anticlockwise direction

Question 7

What does the principle of moments state?

Answer 7

That for a system to be in equilibrium, the sum of clockwise moments must equal the sum of the anticlockwise moments

Question 8

What is a couple?

Answer 8

Two equal forces which act in opposite directions on an object but not through the same point

Question 9

What does this mean that a couple produces?

Answer 9

A turning effect

Question 10

What is this effect referred to as?

Answer 10

Torque