In physics, what is work?

In physics, what is work?

• A. Unit of force
• B. Change in momentum
• C. Mechanism for the transfer of energy
• D. Rate of energy transfer

Answer: (C)

Work in physics is the transfer of energy that happens when a force moves an object through a distance. When the force has a component in the direction of the motion, it transfers energy to the object, and the amount of work is given by the dot product F·d (often written as F d cos(theta)). If there is no displacement or the force is perpendicular to the motion, no work is done. If the force acts opposite the motion, the work is negative, removing energy from the object. This concept distinguishes work from a unit of force (the Newton), from a change in momentum (impulse), and from the rate of energy transfer (power).

Work in physics is the transfer of energy that happens when a force moves an object through a distance. When the force has a component in the direction of the motion, it transfers energy to the object, and the amount of work is given by the dot product F·d (often written as F d cos(theta)). If there is no displacement or the force is perpendicular to the motion, no work is done. If the force acts opposite the motion, the work is negative, removing energy from the object. This concept distinguishes work from a unit of force (the Newton), from a change in momentum (impulse), and from the rate of energy transfer (power).