A 75.0 -kg man is riding an escalator in a shopping mall....

A 75.0 -kg man is riding an escalator in a shopping mall. The escalator moves the man at a constant velocity from ground level to the floor above, a vertical height of $4.60 \mathrm{m}$. What is the work done on the man by (a) the gravitational force and (b) the escalator?

Labs

Want to see this concept in action?

NEW

Explore this concept interactively to see how it behaves as you change inputs.

View Labs

Key Concepts

Gravitational Potential Energy

Gravitational potential energy is the energy an object possesses due to its location within a gravitational field. It is given by the product of the object's mass, the acceleration due to gravity, and the height above a reference level. This energy represents the work required to raise the object against the gravitational force and is a key factor in energy conservation calculations in mechanics.

Work-Energy Theorem and Constant Velocity Motion

The work-energy theorem states that the net work done on an object is equal to its change in kinetic energy. In scenarios where an object moves at constant velocity, the net work is zero, indicating that any work done by one force is counterbalanced by work done by another. This is important when analyzing systems where energy is transferred between different forms, such as from kinetic to potential energy and vice versa, even though the object's speed remains unchanged.

Work

Work is the energy transferred to or from an object via a force acting through a displacement. It is defined mathematically as the dot product of the force and displacement vectors, meaning that only the component of the force in the direction of the displacement contributes to the work done. This concept is central to understanding how forces affect energy in mechanical systems.

Transcript

Please give Ace some feedback