Centre of mass and centre of gravity

Question 1

Define the centre of gravity

Answer 1

The point at which weight appears to act

Question 2

Describe how you would find the centre of gravity for a plane object

Answer 2

1) Suspend the object from a point and use a plumb line to mark a vertical line on the object
2) Repeat using a different point of suspension
3) The centre of gravity is at the point where the two line intersect

Question 3

Define centre of mass

Answer 3

All of the objects masses concentrated at a single point