Question

A horizontal heavy uniform bar of weight W is supported at its ends by two men. At this instant, one of the men let s go off his end of the rod, the other feels the force on his hand changed to - (a) W (b) W/2 (c) 3W/4 (d) W/3.​

Answer 1

The other feels the force on his hand changed to W/4.

Explanation:

We need to consider the linear acceleration in this problem.

The angular acceleration is given as:

Iα = (wl)/2

Where,

I = Moment of inertia = ml²/3

w = Weight = mg

Now, the angular acceleration is given as:

α = (3g)/(2l)

Now, the linear acceleration is given as:

a = 1/2 × α

a = 1/2 × (3g)/(2l)

∴ a = 3g/4

Now, the normal reaction is given as:

w - N = ma

mg - N = (m × 3g/4)

N = mg/4

∴ N = w/4

Answer 2

Answer:

Explanation:

according to the Newton's third law every action has equal and opposite reaction. So when one man will leave the bar at one end , other end will also experience same reaction. Thus the weight experienced by the other man is also w.