20 terms

Conceptual Physics 12th e. by Paul G. Hewitt
Summary of Terms, Summary of Formulas, and Terms Within the Textbook

Work

The product of the force and the distance moved by the force.

Power

The time rate of work:

(More generally, power is the rate at which energy is expended.)

(More generally, power is the rate at which energy is expended.)

Energy

The property of a system that enables it to do work.

Potential energy (PE)

The energy that something possesses because of its position.

Kinetic energy (KE)

Energy that something possesses because of its motion.

Work-energy theorem

The work done on an object equals the change in kinetic energy of the object.

Law of Conservation of energy

Energy cannot be created or destroyed; it may be transformed from one form into another, but the total amount of energy never changes.

Machine

A device that increases (or decreases) a force or simply changes the direction of a force.

Conservation of energy for machines

The work output of any machine cannot exceed the work input. In an ideal machine, where no energy is transformed into thermal energy.

Efficiency

The percentage of the work put into a machine that is converted into useful work output.

(More generally, useful energy output divided by total energy input.)

(More generally, useful energy output divided by total energy input.)

Joule

The unit of work, also known as a Newton-meter.

Impulse

The product of the force acting on an object and the time during which it acts.

Law of Conservation of Momentum

In the absence of an external force, the momentum of a system remains unchanged.

Elastic Collision

A collision in which colliding objects rebound without lasting deformation or the generation of heat.

Inelastic Collision

A collision in which the colliding objects become distorted, generate heat, and possibly stick together.

Momentum

Inertia in motion. The product of the mass and the velocity of an object.

Impulse-Momentum Relationship

Impulse is equal to the change in momentum of the object that the impulse acts upon. In symbolic notation:

Ft = ∆ mv

Ft = ∆ mv

System

In physics, it may be as tiny as an atom or as large as the universe. We usually refer to it as a the relationship between two objects.

Interaction

Mutual action between objects where each object exerts an equal and opposite force on the other.

Component

Mutually perpendicular vectors, usually horizontal and vertical, whose vector sum is a given vector.