Noadswood Science, 2013

To calculate the centre of mass for a given object

Friday, April 21, 2023

Centre Of Mass

How can you find the centre of mass?

Suspend the shape and a plumb line from the same point and wait until they stop moving – draw a line along the plumb line and then repeat this suspending the shape from a different pivot point

The point where the two lines cross is the centre of mass…

Centre Of Mass

Where is the centre of mass?

The centre of mass hangs directly below the point of suspension (it can be thought of as the point at which the whole mass is concentrated

A freely suspended object will swing until its centre of mass is vertically below the point of suspension: -

Stability

Stability is extremely important in a wide variety of objects (from F1 cars to high chairs) – if there is a high centre of mass then issues can occur…

Complete the centre of mass questions…

Centre Of Mass

1. Only c will topple over because its centre of mass it ‘outside’ the base of the object

Centre Of Mass

2. In the centre where the two lines cross

3. Use a pin to freely suspend the card and draw a vertical line downwards from the pin. Repeat this procedure suspending from a different point. Where the two lines cross is the centre of mass

4. A lower centre of mass will mean that the bus is more stable and will not topple over until tilted at a greater angle

Centre Of Mass

5. The easiest method is to measure the angle between the floor and the line joining the bottom of the left wheels of the bus (the pivot) to the centre of mass, as shown in the diagram. Then take this angle (38o) away from 90o. You would have to tilt the bus by that angle to position the centre of mass vertically above the left wheels.

90o – 38o = 52o