Turning Forces and Centre of Mass

Question 1

What is a moment?

Answer 1

The turning effect of a force

Question 2

Moment = (formula)

Answer 2

Force * perpendicular DISTANCE from the line of action of the force to the point

Question 3

What are the units/symbol equation for moments?

Answer 3

MM = F*d
Nm = N * m

Question 4

Describe the moment on a spanner

Answer 4

The force on the spanner cause a turning effect (moment) on the nut (acts as the pivot). A larger force = a larger moment

Question 5

What would change if you had a longer spanner?

Answer 5

The same force can exert a larger moment because the distance from the pivot is greater

Question 6

To get the [ ] moment you need to push at right angles ([ ]) to the spanner
Pushing at any other angle means a [ ] moment because the perpendicular distance between the line of action and the [ ] is [ ]

Answer 6

maximum
perpendicular

smaller
pivot
smaller.

Question 7

The centre of mass hangs directly below the [ ]

Answer 7

point of suspension

Question 8

Centre of mass is…

Answer 8

The point at which the whole mass is concentrated

Question 9

A freely suspended object will swing until its [ ] is [ ] the point of suspension

Answer 9

centre of mass

vertically below

Question 10

The object’s [ ] acts at a distance from the pivot which creates a [ ] about the pivot. Which makes it swing until the [ ] is at its lowest (directly under the pivot)

Answer 10

weight
moment
centre of mass

Question 11

How do you find the centre of mass of a flat object?

Answer 11

1) Suspend the shape and a plumb line from the same point, and wait until they stop moving
2) Draw a line along the plumb line
3) Do the same thing again, but suspend thee shape from a different pivot point
4) The centre of mass is where your two lines cross

Question 12

On symmetrical shapes where is the centre of mass?

Answer 12

Where the lines of symmetry cross