Ch 5 Turning Effect of Forces#

Question 1

What is the turning effect of a force also known as?

Answer 1

moment or torque

Question 2

What is the formula for the moment of a force ?

Answer 2

moment = Force X Perpendicular Distance

moment = F d

Not to be confused with work done from Chapter Energy

Question 3

In what direction can a force turn about a pivot ?

Answer 3

Clockwise and anti-clockwise

Anti-clockwise is aka counterclockwise.

Question 4

Define the principle of moments

Answer 4

When an object is in equilibrium, the sum of clockwise moments about a pivot is equal to the sum of anti-clockwise moment about the same pivot.

(formula)
By Principle of Moments
Taking moments about the pivot
total clockwise moments = total anti-clocwise moments

Question 5

Define center of gravity.

Answer 5

It is a point in an object where the whole weight of the object seems to act.

center of gravity for various shapes

Question 6

What are the two conditions for equilibrium?

Answer 6

1) No resultant force
2) No resultant moments

Question 7

What is needed fn order for a force to produce a moment?

Answer 7

pivot