Energy Stores and Systems

Vocabulary flashcards defining energy stores, systems, and energy transfer mechanisms based on the provided lecture notes.

System

A single object (e.g. the air in a room) or a group of objects (e.g. two colliding vehicles) that you are interested in.

Closed System

A system where neither matter nor energy can enter or leave, meaning the net change in the total energy is always zero.

Thermal Energy Store

An energy store related to the heat of an object or system, such as water heated in a kettle.

Kinetic Energy Store

An energy store associated with a moving object, such as a moving ball or the wheels of a vehicle.

Gravitational Potential Energy Store

An energy store filled when an object is raised or held at a height in a gravitational field.

Elastic Potential Energy Store

An energy store found in objects that are stretched, compressed, or distorted.

Chemical Energy Store

An energy store present in chemical bonds, such as in food, fuel, batteries, or a person's muscle tissues.

Magnetic Energy Store

An energy store associated with interacting magnetic poles.

Electrostatic Energy Store

An energy store associated with interacting electric charges.

Nuclear Energy Store

An energy store contained within atomic nuclei.

Work Done

Another way of saying energy transferred, which can happen when current flows or when a force moves an object.

Energy Transfer in Throwing a Ball

The initial force exerted by a person does work, transferring energy from the chemical energy store of the person's arm to the kinetic energy store of the ball and arm.

Energy Transfer in a Dropped Ball

As the ball is accelerated by gravity, the gravitational force does work, transferring energy from the ball's gravitational potential energy store to its kinetic energy store.

Energy Transfer in Car Braking

Friction between a car's brakes and its wheels does work as it slows down, transferring energy from the wheels' kinetic energy stores to the thermal energy store of the surroundings.

Energy Transfer in a Car Collision

The normal contact force between the car and object does work, transferring energy from the car's kinetic energy store to the elastic potential and thermal energy stores of the object and car body, with some transferred away by sound waves.