Physics: Forces, Motion, and Energy Review

Vocabulary flashcards generated from lecture notes covering key definitions in physics including forces, Newton's laws, energy types, and collision properties.

Force

A measure of the interaction between two objects, or the influence that one object has on another; a vector quantity that has both magnitude and direction and can change an object's speed, direction, or both.

Net force

The overall force acting on an object, calculated as the vector sum of all individual forces acting on it.

Balanced forces

Forces that are equal in strength but act in opposite directions, resulting in a net force of $0\,\text{N}$ and causing no change in the object's motion.

Unbalanced force

A state where the force applied in one direction is greater than the force applied in the opposite direction, producing a net force greater than $0\,\text{N}$ and changing the object's motion.

Friction

The resistance that one surface or object encounters when moving over or rubbing against another, which acts to slow an object down.

Gravity

The force of attraction that pulls a body towards the center of the earth, or towards any other physical body having mass.

Air Resistance

The force that acts in opposition to the motion of an object moving through the air.

Inertia

The principle that an object will stay in motion or at rest until an outside force changes its speed or direction.

Motion

The phenomenon in which an object changes its position with respect to time.

Newton's 1st Law

The law stating that every object will remain at rest or in uniform motion in a straight line unless compelled to change its state by the action of an external force.

Newton's 2nd Law

The law stating that the acceleration of a body is directly proportional to the net force acting on the body and inversely proportional to the body's mass.

Newton's 3rd Law

The law stating that for every action, there is an equal and opposite reaction.

Mass

The amount of matter present in any object or body.

Momentum

Described as 'mass in motion', defined mathematically as $\text{momentum} = \text{mass} \times \text{velocity}$.

Speed

The rate of change of position of an object in any direction.

Velocity

The speed of an object in a given direction.

Acceleration

The rate at which velocity changes with time, in terms of speed, direction, or both.

Contact force

A push or pull exerted on an object when two objects are physically touching each other.

Non-contact force

A push or pull exerted on an object when the objects are not physically touching.

Applied force

A force that occurs when a person or another object directly applies a push or pull onto something.

Potential energy

The stored energy that an object possesses because of its position or state.

Kinetic energy

The energy of motion that is produced when potential energy is used and converted.

Joule

The standard SI unit for measuring energy (abbreviated $J$), defined as the work done by a force of one newton moving an object one meter.

Inelastic Collision

A collision in which momentum is conserved, but some kinetic energy is transformed into other energy forms such as heat, sound, light, or deformation.