A man holds a child on shoulders while watching a football match. How much work has he done if the game last for 2 hours

zero

If there is no motion, no work is done.

To determine the amount of work done by the man, we need to have information about the force exerted and the displacement involved. Without this information, we cannot accurately determine the amount of work done.

In physics, work is defined as the product of force and displacement in the direction of the force. Essentially, work measures the energy transferred to or from an object when force is applied over a distance.

If we assume that the man is standing still while holding the child on his shoulders, and there is no vertical displacement (i.e., he does not lift or lower the child), then the force exerted by him would be equal to the weight of the child. This can be calculated using the formula:

force = mass * acceleration due to gravity

Typically, acceleration due to gravity is approximately 9.8 meters per second squared. To find the mass of the child, we would need additional information.

However, it's important to note that if the man is simply standing still, then no work is being done according to the physics definition of work. Work is only done when there is a force causing a displacement.

So, without more information about the force exerted or the displacement involved, we cannot determine the amount of work done by the man.