Paper 1 Definitions

Normal Force

Force a surface exerts perpendicular to it.

Frictional Force

is the force that opposes the motion of an object and acts parallel to the surface.

Static Friction

the force that opposes the tendency of motion of a stationary object relative to a surface.

Kinetic Friction

the force that opposes the motion of a moving object relative to a surface.

Newton 1

a body will remain at rest or in uniform motion unless a non-zero resultant/net force acts on it.

Newton 2

when a net force acts on an object, the object will accelerate in the direction of the force and the acceleration is directly proportional to the force and inversely proportional to the object's mass.

Newton 3

when object A exerts a force on object B, object B simultaneously exerts an oppositely directed force of equal magnitude on object A.

Newton’s Law of Universal Gravitation

each body in the universe attracts every other body with a force that is directly proportional to the product of their masses and inversely proportional to the square of the distance between their centres.

Weight

the gravitational force that the Earth exerts on an object on or near its surface.

Momentum

the product of an object's mass and its velocity, and it is a vector quantity.

Impulse

the product of the resultant/net force acting on an object and the time during which the force acts.

Projectile

an object that has been given an initial velocity and then moves under the influence of the gravitational force only.

Free Fall

motion during which the only force acting on an object is the gravitational force.

Work

the product of the magnitude of a constant force, the displacement, and the cosine of the angle between the force and the displacement.

Work energy Theorom

the work done on an object by a net force is equal to the change in the object's kinetic energy.

Conservative Forces

a force for which the work done in moving an object between two points is independent of the path taken

Power

a force for which the work done in moving an object between two points is independent of the path taken

Doppler Effect

change in frequency (or pitch) of sound detected by a listener because the sound source and the listener have different velocities relative to the medium of sound propagation.

None-conservative forces

change in frequency (or pitch) of sound detected by a listener because the sound source and the listener have different velocities relative to the medium of sound propagation.

Coulomb’s Law

the magnitude of the electrostatic force exerted by one point charge on another is directly proportional to the product of the magnitudes of the charges and inversely proportional to the square of the distance between them.

Electric field

a region of space in which an electric charge experiences a force, and its direction is the direction that a positive test charge would move.

Ohm’s Law

the potential difference across a conductor is directly proportional to the current in the conductor at constant temperature.

Electromagnetic Induction

the process by which a current is induced in a conductor by a changing magnetic field.

Motor Effect

the phenomenon where a current-carrying conductor placed in a magnetic field experiences a force.

RMS (Root means square)

value of an alternating voltage or current is the value that dissipates the same amount of energy as an equivalent direct current.

Photoelectric effect

the process whereby electrons are ejected from a metal surface when light of a suitable frequency is incident on that surface

Threshold Frequency

the minimum frequency of light needed to emit electrons from a certain metal surface.

Work function

the minimum energy that an electron in a metal needs to be emitted from the metal surface.

Absorption Spectrum

formed when certain frequencies of electromagnetic radiation passing through a substance are absorbed.

Emission Spectrum

formed when certain frequencies of electromagnetic radiation are emitted due to an atom making a transition from a higher energy state to a lower energy state.