Question

Two people carry a heavy electric motor by placing it on a light board 1.80 m long. One person lifts at one end with a force of 350 N, and the other lifts the opposite end with a force of 620 N.
What is the weight of the motor?

Answer 1

Answer:

$W=970\ N$

Explanation:

When two people carry a weight placing it on a very light board then we neglect the weight of the board and the board acts like a beam with two mass placed over it and two end point supports are here provided by men.

Then balancing the forces in the vertical direction, weight of the motor is:

$W=350+620$

$W=970\ N$

These men are able to carry the motor in equilibrium condition because they have placed the motor (considering it a point mass) at a position such that the moment due to the lifting forces are equal and opposite.