If an elevator is moving upward at a constant speed, how does the upward force exerted on a man's feet compare to his weight?

When an elevator is moving upward at a constant speed, it is important to consider the concept of equilibrium in physics. In this situation, the forces acting on the man inside the elevator are balanced. The force exerted on the man's feet is the normal force, which is the force that the elevator floor applies to support him against gravity.

Since the elevator is not accelerating—moving upward at a constant speed—the net force acting on the man is zero. According to Newton's first law, when there is no net force acting on an object, the object either remains at rest or continues to move at a constant velocity. This indicates that the upward force, or the normal force, must be equal to the downward force due to gravity, which is the weight of the man.

In simpler terms, if the normal force were greater than his weight, he would be accelerating upward, and if it were less, he would be accelerating downward. Since the elevator's movement is constant, the forces are balanced, making the upward force equal to the man's weight. This understanding of forces is fundamental in introductory physics and highlights the relationship between force, weight, and motion in a system experiencing no acceleration.