Turning Forces

Question 1

what is the turning effect of a force?

Answer 1

moment of a force

Question 2

moment…

Answer 2

turning effect produced by an force applied

Question 3

what do moments act upon and in which directions?

Answer 3

moments act about a pivot, either in a clockwise direction or a anti-clockwise direction

Question 4

calculate the moment of a force?

Answer 4

moment of a force (Nm) = force (N) x perpendicular distance from pivot (m)

Question 5

pivot…

Answer 5

the point around which the object can rotate or turn

Question 6

force measured in…

Answer 6

Newtons (N)

Question 7

distance measured in…

Answer 7

Metres (m)

Question 8

moment measured in…

Answer 8

Newton-metres (Nm)

Question 9

Calculate the moment:

Answer 9

Perpendicular distance from pivot to force d = 0.50 m.

Force F = 10 N

Moment = Fd

Moment = 10 N x 0.50 m

Moment = 5 Nm

This is a clockwise moment.

The force will rotate the object in a clockwise direction about the pivot.

Question 10

A force of 15 N is applied to a door handle, 12 cm from the hinge.

Calculate the moment of the force.

Answer 10

Perpendicular distance from pivot to force d = 12 cm = 0.12 m.

Turning force F = 15 N.

Moment = Fd.

Moment = 15 N x 0.12 m.

Moment = 1.8 Nm.

The moment of the force is 1.8 Nm.

Question 11

what will happen to a ‘see-saw’ by comparing the clockwise and anti-clockwise moments.

Answer 11

If the clockwise moment is larger than the anti-clockwise moment, the see-saw will turn clockwise, vice versa.

e.g.
clockwise 43Nm while anti-clockwise 41Nm

the see-saw will turn to the right because:
43Nm > 41Nm