Question

Write an expression for the magnitude of the normal force, fn, acting on the block, in terms of f2 and the other variables of the problem. assume that the surface it rests on is rigid.

Answer 1

The magnitude of the normal force, fn, for a block on a horizontal rigid surface with a gravitational force fg of 40 N is equal to the gravitational force, making fn also 40 N.

Step-by-step explanation:

The magnitude of the normal force, fn, acting on a block on a horizontal surface is equal to the weight of the block when the surface is rigid and there are no other vertical forces except gravity. If we denote the gravitational force as fg, which in this case is 40 N, and given that there are no additional vertical forces and the surface is horizontal, the normal force will balance the gravitational force. Therefore, we have fn = fg, so the normal force fn is also 40 N.

In scenarios where there are additional vertical forces or the surface is not horizontal, the normal force is calculated by summing all vertical forces, where forces pushing the block into the surface increase the normal force and forces lifting the block reduce the normal force. However, in this example, such complexities are absent, making the calculation straightforward.

Answer 2

If the force is fn, then it acting on the block, in the term of f2 and the other variables of the problems. then we assume the surface is rest on it's rigid, then the magnitude of the force is, fn =f2 sin(?) +m g