MYP Physics Forces and Energy Key Definitions

Acceleration is defined as the rate of change of velocity.

How close a measurement is to the true or accepted value.

Air resistance is the frictional force acting on objects moving through air.

A method of storing energy by using surplus electricity to compress air into a cavern or vessel, then releasing it later to drive a turbine and generate electricity.

Compression is a pushing force in a squashed object.

Energy cannot be created or destroyed. It can only be converted from one form to another.

The variable that is measured; it may change in response to the independent variable.

Efficiency is the proportion of input energy transferred into useful output energy.

A source from which energy can be obtained for human use (for example, coal, sunlight, moving water, uranium).

Observations and measurements that support, contradict, or refine a hypothesis or theory.

An experiment is a controlled way to collect measurements so you can decide whether a claim is supported.

A region of space where an object experiences a force because of the presence of another object (for example, a magnet or an electric charge).

A force is a mechanical interaction between two objects or bodies.

Fossil fuels are ancient energy sources formed over millions of years from the remains of plants and animals exposed to heat and pressure beneath Earth's surface

A free-body diagram (FBD) is a simplified drawing that shows an object as a dot or box, with arrows for all external forces acting on it.

Freefall occurs when gravity is the only force acting on an object.

Friction is a force that opposes motion between surfaces in contact.

The gravitational force per unit mass at a point in a gravitational field and is measured in $\text{N kg}^{-1}$.

Gravitational potential energy is the energy stored due to the position of an object in a gravitational field.

Gravity is the interaction that makes objects fall, gives us a sense of "up" and "down," and keeps moons, planets, and galaxies in orbit.

A greenhouse gas is a gas that contributes to the greenhouse effect by absorbing infrared radiation

A testable prediction or proposed explanation that can be checked using observations or experiments.

The variable the experimenter deliberately changes to see its effect.

Inertia is the tendency of an object to resist changes in its motion.