Question

Questions 1. Does a man do work when he carries a 75 N bag horizontally for 5 m? Why / why not?​

Answer 1

Ответ:

No. Because the angle between force and displacement is 90 degrees.

Answer 2

Yes, a man does work when he carries a 75 N bag horizontally for 5 m.

Work is defined as the product of force and displacement in the direction of the force. In this case, the man exerts a force of 75 N horizontally to counteract the downward force of gravity acting on the bag. The bag is displaced horizontally for a distance of 5 m.

Since the force exerted by the man and the displacement of the bag are in the same direction, work is being done. The formula for work is:

Work = Force x Displacement x cos(theta)

In this case, theta is the angle between the force applied and the direction of displacement, which is 0 degrees since the force and displacement are in the same direction. The cosine of 0 degrees is 1, so the formula simplifies to:

Work = Force x Displacement

Therefore, the work done by the man is:

Work = 75 N x 5 m = 375 Joules

So, the man does work of 375 Joules when carrying the 75 N bag horizontally for 5 m.