Determination of unknown mass of an object using principles of moments Aim: Determine of unknown mass of an object using principles of moments
Inferences
Moment of force is measure of its tendency to rotate an object about some point.
It can be calculated using the following equation:

Moment in equilibrium is sum of moment rotating clockwise equals sum of moment rotating anticlockwise.
Hypothesis
Sum of moment rotating anticlockwise equal to sum of moment rotating clockwise.
Sum of force acting upward equal to sum of force acting downward.
The moment of force is equal to the magnitude of the force multiplied by the perpendicular distance between its line of action and the axis of rotation.

Apparatus
Meter rule
clamp and stand
nail or pin
Standard mass e. g. 200 g mass
Unknown mass
loops of thread
Procedure
1.Set up the apparatus as Figure 1.
2.Ensure that the beam is in horizontal position and at the same height.
3.Place the standard mass, to the left, 45cm from the centre of the rule.
4. Hang the object with unknown mass to the right.
5.Move the mass across the rule till the metre rule is balanced horizontally.
6.Record the distance at the meter balanced
7. Repeat the above procedures using different masses

fig 1.

Data collection table

Distance (cm)
Standard mass (g)
Distance cm
Unknown mass (g)​