Work and Energy Flashcards

A set of vocabulary flashcards based on the Chapter 1 lecture notes covering work, energy, power, and simple machines.

Energy

The capability of an object to do useful work.

Work

The transfer of energy by applying a force to an object over a distance, represented by the equation $W = F_{\parallel} \times d$.

Joule

The SI unit of quantify energy and work, which is equal to a Newton-meter ($N \cdot m$) or a kilogram meter-squared per second-squared ($kg \cdot m^2/s^2$).

Scalar Quantities

Physical concepts that have no associated direction, only a magnitude or strength; examples include energy and work.

Potential Energy

Stored energy that exists based on the arrangement or configuration of an object.

Kinetic Energy (KE)

Energy that objects possess by virtue of their motion, quantified by the equation $\frac{1}{2} m v^2$.

Electric Potential Energy

Stored energy resulting from placing charged particles some distance apart from each other.

Chemical Energy

A type of stored energy based on the configuration of atoms or molecules, such as that found in gasoline or food.

Nuclear Energy

The energy stored in the nucleus of an atom, released during radioactive decay, fission, or fusion.

Elastic Potential Energy

Energy stored in the configuration of a deformable object, such as a compressed or stretched spring.

Gravitational Potential Energy (GPE)

Stored energy due to the gravitational attraction between the Earth and other objects of mass, calculated as $GPE = m \cdot g \cdot h$.

Heat (Thermal Energy)

Energy that moves between objects of different temperatures, often considered wasted energy when generated by friction.

Conservation of Energy

The principle stating that energy cannot be created or destroyed, only converted from one form to another.

Mechanical Energy

A descriptive quantity representing the sum of the gravitational potential energy and kinetic energy of an object.

Work-Energy Theorem

A physics principle stating that work performed on an object is equal to its change in kinetic energy ($W = \Delta KE$).

Power (P)

A measure of how quickly work is done, expressed by the equation $P = \frac{W}{t}$.

Watt (W)

The SI unit for power, which is equivalent to one Joule per second ($J/s$).

Simple Machine

A device used to change either the direction or magnitude of an applied force.

Mechanical Advantage (MA)

A unitless ratio used to quantify the force multiplication of a machine, calculated as $MA = \frac{\text{output force}}{\text{input force}}$.

Efficiency (e)

A unitless quantity, often expressed as a percentage, that measures how well work input is converted to work output: $e = \frac{\text{work output}}{\text{work input}}$.

Lever

A simple machine that uses a rigid bar and a fulcrum to lift heavy objects using a smaller input force.

Wheel and Axle

A simple machine where a linear force is used to cause rotation, often allowing for force multiplication.

Pulley

A simple machine that can change the direction of a force or multiply it depending on the number of load strings used.

Inclined Plane

Also known as a ramp, a simple machine that reduces the force required to move an object by increasing the distance of travel.

Wedge

A simple machine used to split objects apart by transmitting force from a blunt edge to a pointy edge.

Screw

A simple machine that converts rotational motion into linear motion.