Question

A meter rule is supported on a knife egde placed at 30cm graduation.it is found that meter rule balances horizontally when a mass which has weight of 25N is suspended at 10cm graduation.what is the moment of force due to mass of rule and it's mass respectively

Answer 1

Answer:

ANSWER

Let, W be the mass of uniform scale,

When the edge is placed at 58cm mark and 20g weight suspended at one end, then uniform scale would be balaced.

Applying here the principle of moments:

The uniform scale weight would be balanced at mid point i.e. 50cm of the scale.

A weight of 20g is placed at 58cm mark.

So the clockwise moment due to mass of the scale will be W(50−42)=8W

The anticlockwise moment due to mass 20g will be 20×(50−8)=840.

For equilibrium, clockwise moment = anticlockwise moment

So,

Wx8=840

W=105g

The wight of the uniform meter =105g.