Question

In: Physics

Two people are carrying a uniform 3 m long steel beam that has a total mass...

Two people are carrying a uniform 3 m long steel beam that has a total mass of 32.1 kg. One person is supporting it at the far left end with an upward force of 120 N, while the second one is supporting it somewhere near the right end with an unknown force.

How much force is required from the second person in order to balance the beam? H

ow far from the right end must the second person lift in order to balance the beam?

Expert Solution

(a) Given the mass of the rod (m) = 2.1kg. So the weight of the rod acting downwards is

The upward force given by the person supporting at the far left end is F1 = 120N. Let F2 be the upward force given by the person somewhere in the right end.

For the system to be in equilibrium, the net force on the system should be zero. Therefore,

So the force required from the second person inorder to balance the beam is 194.58N.

(b) Since the rod is uniform, its weight will be acting downwards from the centre. Given the length of the rod L = 3m. The first person is at the far left end. So the person is at a distance L/2 from the centre. Let the second person be at a distance x from the centre of the rod.

For the system to be in equilibrium, the net torque on the system should be zero. Taking torque about the centre of the rod,

So second person is lifting the rod at a distance 0.92m to the right from the centre of the rod. So the distance of the second person from the right end of thr rod is,

The second person is lifting the rod at a distance of 0.58m from the right end.

genius_generous answered 2 years ago

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