N
Natural frequency
The frequency of vibration of an elastic object that depends on the size, composition, and shape of the object.
Negative electric charge
One of the two types of electric charge; repels other negative charges and attracts positive charges.
Negative ion
Atom or particle that has a surplus, or imbalance, of electrons and, thus, a negative charge.
Net force
The resulting force after all vector forces have been added; if a net force is zero, all the forces have canceled each other and there is not an unbalanced force.
Neutron
Neutrons are sub-atomic particles. They are uncharged.
They have a mass of mn = 1.675 x 10-27 kg.
Newton
Sir Isaac Newton, 1642-1727. Newton tried farming before going on to develop his three Laws of Motion. Newton also contributed to other branches of science and maths.
Newton
The newton (N) is the SI unit of force. An unbalanced force of 1 newton will cause a mass of 1 kg to accelerate at 1ms-2.
Newton Balance
This is a spring balance. It can be used to measure force, including weight forces. All forces are measured in newtons.
Newton's First Law
If the forces acting on an object are all balanced, then the object will not change in its motion. It will not speed up, slow down, change direction or shape. IF it is not moving, then it will stay stationary.
Newton's law of gravitation
The gravitational force of attraction acting between any two particles is directly proportional to the product of their masses, and inversely proportional to the square of the distance between them. The force of attraction acts along the line joining the two particles. Real bodies having spherical symmetry act as point masses with their mass assumed to be concentrated at their center of mass.
Newton's Second Law
If forces are not balanced on an object then it will either speed up, slow down or change direction - this means it will have to accelerate.
Newton's third law of motion
To every action there is an equal and opposite reaction. The action and reaction act on two different bodies simultaneously.
Noise
Sounds made up of groups of waves of random frequency and intensity.
Non-Renewable Energy Sources
An energy resource that is not replaced or is replaced only very slowly by natural processes. Primary examples of non-renewable energy resources are the fossil fuels--oil, natural gas, and coal.
Noninertial frame
An accelerating frame of reference, in which Newton's first law is violated.
Non Uniform Acceleration
When the velocity of a body increases by unequal amounts in equal intervals of time, it is said to have non-uniform acceleration.
Nonuniform circular motion
Circular motion in which the magnitude of the velocity vector changes.
Non Uniform Speed
When a body travels unequal distances in equal intervals of time then it is said to have non-uniform speed.
Non Uniform Velocity
When a body covers unequal distances in equal intervals of time in a particular direction, or when it covers equal distances in equal intervals but changes it's direction it is said to have non uniform velocity.
Normalization
The property of probabilities that the sum of the probabilities of all possible outcomes must equal one.
Normal force
The force that keeps two objects from occupying the same space.
Normal Line
In optics and wave applications, the normal line is an imaginary line drawn at right angles to a surface. If the surface is curved, then the tangent to the surface must be drawn first, with the normal being drawn at right angles to the tangent.
Normal
A line perpendicular to the surface of a boundary.
NOT gate (inverter)
The NOT gate or inverter is a digital logic gate that implements logical negation.
Nuclear Chain Reaction
A chain reaction refers to a process in which neutrons released in fission produce an additional fission in at least one further nucleus. This nucleus in turn produces neutrons, and the process repeats. The process may be controlled (nuclear power) or uncontrolled (nuclear weapons).
Nuclear Energy
Nuclear energy is the energy contained within the nucleus of an atom. It can be released in nuclear fission or nuclear fusion.
Nuclear fission
Nuclear reaction of splitting a massive nucleus into more stable, less massive nuclei with an accompanying release of energy.
Nuclear force
One of four fundamental forces, a strong force of attraction that operates over very short distances between subatomic particles; this force overcomes the electric repulsion of protons in a nucleus and binds the nucleus together.
Nuclear fusion
Nuclear reaction of low mass nuclei fusing together to form more stable and more massive nuclei with an accompanying release of energy.
Nuclear reactor
Steel vessel in which a controlled chain reaction of fissionable materials releases energy.
Nucleons
Name used to refer to both the protons and neutrons in the nucleus of an atom.
Nucleus
The center of an atom. The nucleus contains tiny particles called protons and neutrons. Orbiting around the nucleus are electrons.