Investigating Centre of Gravity (Cambridge (CIE) O Level Physics): Revision Note

Investigating the Centre of Gravity

• When an object is suspended from a point, the object will always settle so that its centre of gravity comes to rest below the pivoting point

• This can be used to find the centre of gravity of an irregular shape:

Method for Finding the Centre of Gravity for Irregular Shapes

Diagram showing an experiment to find the centre of gravity of an irregular shape

• The irregular shape (a plane laminar) is suspended from a pivot and allowed to settle

• A plumb line (lead weight) is then held next to the pivot and a pencil is used to draw a vertical line from the pivot (the centre of gravity must be somewhere on this line)

• The process is then repeated, suspending the shape from two different points

• The centre of gravity is located at the point where all three lines cross