Work, Power, and Energy

Front

Work Noun

---

[wurk]

Back

Work

---

The transfer of energy that occurs when a force is applied to an object, causing displacement in the force's direction.

---

Example: This diagram shows different types of job experiences, which relates to the everyday meaning of 'work' but not the scientific definition used in physics.

Front

Energy Noun

---

[en-er-jee]

Back

Energy

---

The quantitative property that must be transferred to an object in order to perform work on, or to heat, the object.

---

Example: This diagram shows how electrical energy entering a light bulb is converted into two different forms: light energy and heat energy.

Front

Joule Noun

---

[jool]

Back

Joule

---

The SI unit of work or energy, equal to the work done by a force of one newton acting over one meter.

---

Example: This image shows how to calculate energy in Joules by multiplying power in Watts by time in seconds, using the formula Energy = Power × Time.

Front

Kinetic Energy Noun

---

[ki-net-ik en-er-jee]

Back

Kinetic Energy

---

The form of energy that an object possesses due to its motion, which is dependent on its mass and velocity.

---

Example: An archer releases an arrow, converting stored potential energy into kinetic energy, which is the energy of the arrow's motion.

Front

Potential Energy Noun

---

[po-ten-shul en-er-jee]

Back

Potential Energy

---

The stored energy an object holds due to its position, state, or internal structure, ready to be converted into work.

---

Example: An object's potential energy, or stored energy, is greater when it has more mass or is at a greater height above the ground.

Front

Mechanics Noun

---

[muh-kan-iks]

Back

Mechanics

---

The branch of physics concerned with the behavior of physical bodies when subjected to forces and their subsequent effects on motion.

---

Example: This image shows an apple falling due to the force of gravity, demonstrating mechanics: the study of motion and the forces causing it.

Front

Force Noun

---

[fors]

Back

Force

---

An interaction, such as a push or a pull, that, when unopposed, will change the motion of an object.

---

Example: A person applies a force (a push) to an object, which is the first step required to perform work on that object.

Front

Displacement Noun

---

[dis-pleys-muhnt]

Back

Displacement

---

A vector quantity representing the shortest distance and direction from an object's initial position to its final position.

---

Example: A person travels from home to school and back. Although they covered a distance, their displacement is zero because their starting and final positions are the same.

Front

Friction Noun

---

[frik-shuhn]

Back

Friction

---

A force that opposes the relative motion or tendency of such motion between two surfaces that are in contact.

---

Example: This diagram shows a force pushing a crate, while friction is the opposing force that resists this motion. The magnified view reveals friction's cause: the microscopic roughness of the two surfaces rubbing together.

Front

Power Noun

---

[pou-er]

Back

Power

---

The rate at which work is performed or energy is transferred, measured as the amount of work done per unit time.

---

Example: This image describes five types of social and political power, such as 'power over' (control) and 'power with' (collaboration), which is incorrect for the scientific context of Work, Power, and Energy.