Physics Concepts: Motion, Forces, and Energy

A collection of flashcards featuring key terms and definitions related to motion, forces, and energy from physics.

Speed

The distance travelled by an object per second, typically expressed in metres per second (m/s).

Average Speed

Total distance travelled divided by the time taken for the whole journey.

Instantaneous Speed

The speed of an object at a particular point in time during its journey.

Scalar Quantity

A physical quantity completely described by its magnitude, like distance or speed.

Vector Quantity

A physical quantity described by both magnitude and direction, like displacement or velocity.

Acceleration

The rate of change of velocity of an object, measured in metres per second squared (ms-2).

Force

An interaction that changes the motion of an object, measured in newtons (N).

Friction

A resistive force that opposes the motion of an object, acting in the opposite direction to the motion.

Newton's First Law of Motion

An object will remain at rest or in uniform motion unless acted upon by an external force.

Mass

The amount of matter in an object, measured in kilograms (kg).

Weight

The force of gravity acting on an object's mass, measured in newtons (N).

Gravitational Field Strength (g)

The force exerted by gravity per unit mass, typically on Earth's surface it equals 9.8 N/kg.

Work Done

The amount of energy transferred when a force moves an object a certain distance, calculated as work = force x distance.

Kinetic Energy

The energy of an object due to its motion, calculated as KE = 0.5 x m x v^2.

Potential Energy

The stored energy of an object due to its position or configuration, such as gravitational potential energy.

Specific Heat Capacity

The amount of energy required to raise the temperature of 1 kg of a substance by 1°C.

Light Year

A measure of distance, specifically the distance light travels in one year, approximately 9.46 trillion kilometers.

The Big Bang Theory

The leading explanation of the origin of the universe, suggesting it began from an extremely hot and dense state about 14 billion years ago.

Electromagnetic Spectrum

The range of all electromagnetic radiation wavelengths, including radio waves, infrared, visible light, ultraviolet, X-rays, and gamma rays.

Satellite Communication

The transmission and reception of signals between ground stations and satellites, often using curved reflectors to focus signals.

Projectile Motion

The motion of an object that is thrown or projected into the air, influenced by gravitational force and having both horizontal and vertical components.

Terminal Velocity

The constant speed reached by an object falling through a fluid when the force of gravity is balanced by the drag force.