EXPERIMENT – 6

AIM:
To find the weight of an unknown object using the principle of moments.

APPARATUS:
Metre scale, retort stand, known weight, unknown weight and a thread for hanging.

PRINCIPLE:

When a body is in equilibrium under the action of a number of forces, then the algebraic sum of moments about any point is zero under the condition of equilibrium. Under this condition :

Load x Load Arm = Effort x Effort Arm

FORMULA:

Ax = By
Where :
A= known weight
b= unknown weight
x= distance of known weight from the fulcrum
y= distance of unknown weight from the fulcrum

PROCEDURE:

1.Hang the metre rod using thread from the stand at the point of the centre of gravity of the metre scale.
2.Suspend the known weight on the left hand side of the fulcrum at distance of x cm from the centre of gravity
3.Suspend the unknown on the right hand side of the fulcrumand balance the scale.
4.Note the distances x and y
5.Calculate the unknown weight

PRECAUTIONS:

1.The experiment should be done away from fans, open windows etc to aviod disturbance due to air currents.
2.The distances x and y from the fulcrum should be carefully noted..
3.The loops of the thread must be parallel to the metre scale markings.

RESULT:

The weight of the unknown object is found to be ________ gf.