centre of mass

Question 1

What will eventually happen to a suspended object that has been released (pushed)?

Answer 1

It will sooner or later come to rest (equilibrium) with its centre of mass directly below the point of suspension

Question 2

Why does the weight of an object not exert a turning effect on it when it is at rest?

Answer 2

Because it’s centre of mass is directly below the point of suspension

Question 3

Why does an object that is turned from its equilibrium position and the released, swing back to this position?

Answer 3

Because it’s weight has a turning effect that returns the object to equilibrium

Question 4

Where is the centre of mass in a symmetrical object?

Answer 4

Along the axis of symmetry, and where multiple axes meet

Question 5

How can the centre of mass of an irregular shape be found?

Answer 5

• the card is freely suspended at rest from a rod through one of its vertices
• its centre of mass will be directly below the rod, which can be seen by using a plumb line to draw the vertical line on the card
• this procedure is repeated with the card suspended from a second vertex to draw a similar line
• the centre of mass is where the two lines meet

Question 6

What is the centre of mass (or the centre of gravity)?

Answer 6

The point at which the an objects mass may be thought to be concentrated