Question

A uniform 2 meter stretcher has a mass of 5 kg. It is used by two persons to carry three masses of 40 kg, 10 kg, and 30 kg, which are located at 0.2 m, 0.5 m, and 1.5 m respectively from the left end of the stretcher. How much support force must each person exert to carry the stretcher?

Answer 1

Length of the stretcher is 2 m and hence it's CG is at 1m.

Let the forces required by the persons carrying them be F1 and F2.

F1 and F2 are acting upwards and all other load and weight is acting downwards.

To be in equilibrium, sum of all the forces must be zero i.e.,

Also, the stretcher must be in rotational equilibrium.

If we consider the point of action of F1 as origin, then the sum of the moments of the forces and the weights must be zero i.e.,

So,