Question

A uniform chain is hanged by two hinges 1m above ground as shown in figure-1. Now its middle point is pulled down, so that its becomes
straight as in figure-2 During pulling downward 0.4 Joules work is done. Mass of chain is 2 kg and length is 2m Find initial height of
COM (in meters) from ground in figure-1.
1m
1m
10.5m
10.5m
Figure-1
Figure-2​

Answer 1

Answer:

At horizontal position the reaction 'N'.

Let the mass of rod is m.

The moment of inertia of rod about the axis passig through the end and perpendicular to its plane is

I= 1/3ml square

For rotation of rod,

Moment of force = Applied torque

⟹x×F=Iα

⟹α= xF=3xF/ml square

=1/3ml square,

Here α is angular acceleration about hinge .

The position of centre of mass is aat the middle.

So the linear acceleration of centre of mass,a=α

a=α 1/2

a=3xF/2ml

So, the net force in vertical on centre of mass is

=ma

3xF/21

This should be equal to N.

So, N= 3xF/21

Explanation:

I hope my answer is correct and helpful to u