Definition

Acceleration:

The rate of change of velocity of a body is called acceleration.

Definition

Artificial satellites:

Man made objects moving in fixed circular orbits around the Earth.

Definition

Atomic Physics:

The branch of Physics that deals with the study of the structure and properties of atoms

Definition

Axis of rotation:

A straight line passing through the points of a rotating rigid body while the other points of the body move in circles about the axis.

Definition

Base quantity

A quantity which can be expressed independently without the reference of any other quantity.

Definition

Base unit:

The units that describe base quantities.

Definition

Buoyant force:

The force acting on an object due to buoyancy of a liquid.

Definition

Centre of gravity:

The point of a body where its weight acts.

Definition

Centre of mass:

A point where an applied force causes the system to move without rotation.

Definition

Centripetal acceleration:

Accelereation produced by the centripetal force.

Definition

Coefficient of linear expansion:

Change in unit length caused by unit kelvin change in temperature.

Definition

Centrifugal force:

According to Newton's third law of motion, there exists a   reaction to the centripetal force. The centripetal reaction that pulls the string outward is sometimes called the centrifugal force.

Definition

Centripetal force:

The force which keeps the body moving in a circular path is called the centripetal force and is given by:

$F_{c}=\frac{mv^{2}}{r}$

Definition

Circular motion:

The motion of a body moving along a circular path is called circular motion.

Definition

Coefficient of volume expansion

Change in unit volume caused by unit kelvin change in temperature.

Definition

Components of a force:

Some forces when added give the resultant force
Definition

Conduction:

Transfer of heat due to interaction of electrons or molecules.

Definition

Convection:

Transfer of heat by actual movement of molecules from a hot place to a cold place is known as convection.

Definition

Couple:

When two equal and unlike parallel forces act at different points of a body they constitute a couple.

Definition

Deceleration:

Negative acceleration.

Definition

Density:

Density is the ratio of mass to volume of a substance. The density of water is
$1000 kgm^{-3}$.

Definition

Derived quantity:

Such quantity which is expressed with reference to base quantities.

Definition

Derived units:

The units used to measure derived quantities.

Definition

Displacement:

The shortest distance between two points.

Definition

Distance:

Length of a path between two points.

Definition

Dynamics:

Study of motion of bodies under the action of forces.

Definition

Efficiency:

The ratio of the useful work done by a device or machine to the total energy taken up by it is called its efficiency.

Definition

Effort arm:

The intermediate distance between fulcrum and effort.

Definition

Effort moment:

Product of effort and effort arm.

Definition

Effort:

Force applied on the machine.

Definition

Elastic potential energy:

Energy of a compressed or strtched spring.

Definition

Elasticity modulus:

Ratio of stress and strain.

Definition

Elasticity:

The property of matter by which matter resists any force which tries to change its length, shape, or volume is called elasticity.

Definition

Electromagnetism:

The branch of physics deals with the study of the charges at rest and in motion, their effects, and their relationship with magnetism.

Definition

Force of gravitation:

The force due to which everybody in the universe attracts every other body.

Definition

Equilibrium:

A state where acceleration of a body is zero.

Definition

Evaporation:

The changing of a liquid into vapors from the surface of the liquid without heating it.

Definition

Field force:

The gravitational pull of the Earth acts on the body whether the body is in contact with the Earth or not.

Definition

Force of gravitation:

The force due to which everybody in the universe attracts every other body.

Definition

Force:

The agent that changes or tends to change the state of a body.

Definition

Fulcrum:

The point around which earth revolves.

Definition

Geophysics:

The branch of physics deals with the study of the internal structure of the Erath and tectonic plate motions etc.

Definition

Gravitational acceleration:

Acceleration is due to the gravity of the Earth.

Definition

Gravitational field strength:

The gravitational force per unit mass.

Definition

Gravitational field:

The field is a region in space in which a particle would experience a gravitational force.

Definition

Gravitational force:

Mutual force of attraction between the objects.

Definition

Gravitational potential energy:

Energy of a body due to its position in the gravitatinal field.

Definition

Heat capacity:

The quantity of thermal energy absorbed by a body for increase in its temperature.

Definition

Heat:

The branch of physics deals with the nature of heat modes of transfer of heat and effects of heat.

Definition

Horizontal component:

The component of a force is along horizontal or x-direction.

Definition

Inertia:

The characteristic of a body resists any change in its state of rest or motion.

Definition

Input:

A work which is done on the machine.

Definition

Internal energy:

The sum of K.E and P.E is associated with the atoms, molecules, and particles of a body.

Definition

Isolated system:

A group of interacting bodies on which no force is acting.

Definition

Joule:

The amount of work done when a force of one newton displaces a body through one meter in the direction of the force.

Definition

Kilowatt-hour:

Work done in one hour at a rate of one kilowatt.

Definition

Kinematics:

Study of motion of bodies without taking into consideration the mass and forces.

Definition

Kinetic energy:

The energy of a body is due to its motion.

Definition

Kinetic friction:

Friction during motion.

Definition

Latent heat of fusion:

The heat required by a unit mass of a substance at its melting point to change it from a solid state to a liquid state is called the latent heat of fusion.

Definition

Latent heat of vaporization:

The quantity of heat required by the unit mass of a liquid at a certain constant temperature to change its state completely from a liquid into a gas is called the latent heat of vaporization.

Definition

Light year:

The unit of distance for celestial bodies equal to $9.46 \times 10^{16}$ m

Definition

Light:

The branch of physics deals with the physical aspects of light and its properties: working and uses of optical instruments.

Definition

Like parallel forces:

Forces acting along parallel lines in the same direction.

Definition

Limiting friction:

The maximum value of static function.

Definition

Line of action of a force:

The line along which a force acts.

Definition

Linear motion:

The motion of a body along a straight line.

Definition

The intermediate distance between fulcrum and load.

Definition

Definition

Resistance or lifted weight.

Definition

Mass:

The characteristic of a body determines the acceleration produced by the application of a force.

Definition

Definition

Mechanics:

The branch of physics deals with the motion of objects, causes, and effects of motion.

Definition

Moment arm:

The perpendicular distance between the axis of rotation and the line of action of the force.

Definition

Momentum:

The product of mass and velocity of a body.

Definition

Motion:

If a body changes its position with respect to its surroundings.

Definition

Negative vector:

A vector which has the same magnitude but opposite direction of another vector.

Definition

Neutral equilibrium:

The condition of a body in which its center of gravity neither rises nor becomes lower than its original position after being disturbed.

Definition

Nuclear physics:

The branch of physics deals with the [properties and behavior of nuclei and the particles within the nuclei.

Definition

Orbital velocity:

The critical velocity of a satellite to keep on moving around the Earth at a specific height.

Definition

Output:

A work which is done by the machine.

Definition

Parallel force:

The forces which are parallel to each other.

Definition

Perpendicular components:

The components of a force are mutually perpendicular to each other.

Definition

Physical quantities:

All measureable quantities.

Definition

Plasma Physics:

The branch of physics deals with the study of production, and properties of the ionic state of the matter-the fourth state of matter.

Definition

Position:

Position means the location of a certain place or object from a reference point.

Definition

Physics:

Physics is a branch of science that deals with matter, energy and their relationship.

Definition

Potential energy:

The energy possessed by a body due to its position.

Definition

Power:

Power is defined as the rate of doing work.

Definition

Prefixes:

The words or letters added before a unit and stand for the multiples or sub-multiples of that unit are known as prefixes. For example, kilo, mega, million, micro, etc.

Definition

Pressure:

Pressure is the normal force acting per unit area. Its SI unit is $Nm ^{-2}$ or pascal (Pa).

Definition

Transfer of heat by infra-red radiators requires no medium for their transmission.

Definition

Random motion:

Motion without any consideration of time and direction.

Definition

Rate of flow of heat:

The amount of heat that flows in unit time.

Definition

Resolution of a force:

Splitting up of a force into its components

Definition

Rest:

If a body does not change its position with respect to its surroundings.concerning

Definition

Resultant force:

The sum of two or more forces is called the resultant force.

Definition

Retardation:

Negative acceleration.

Definition

Rolling Friction:

Rolling friction is the force of friction between a rolling body and a surface over which it rolls. Rolling friction is lesser than the sliding friction.

Definition

Rotatory friction:

The motion in which a body moves around an axis passing through it.

Definition

Scalars

Physical quantities which are described by their magnitude only are known as scalars.

Definition

Scientific method:

Logical applications of arguments that explain a certain phenomenon.

Definition

Scientific notation:

The numbers are written as power or prefix of ten in which there is only one non-zero number before the decimal.

Definition

Simple machine:

A thing which helps in doing work more easily.

Definition

Significant figures

All the accurately known digits and the first doubtful digit in an expression are called significant figures. It reflects the precision of a measured value of a physical quantity.

Definition

Sliding friction:

The friction between two surfaces sliding against each other.

Definition

Sound:

The branch of physics deals with the physical aspects of sound waves.

Definition

Specific heat capacity:

The quantity of heat changes the temperature of one kilogram of mass by 1 K.

Definition

Speed

The distance traveled in any direction by a boy in unit time is called speed.

Definition

stability:

The property of a body that does not undergo any change without the application of an external agency.

Definition

Stable Equilibrium:

The condition of a body in which it comes to its original position after being disturbed.

Definition

Static friction:

The force of friction arises due to an applied external force before motion.

Definition

Strain:

The change in the shape of an object under the action of an external force.

Definition

Stress:

Stress is the deforming force acting per unit area.

Definition

Surface tension:

The force acts along the surface of a liquid.

Definition

Temperature:

The temperature of a body is the degree of hotness or coldness of the body.

Definition

Tensile strain:

The ratio of change of length to the original length is called tensile strain.

Definition

Tension:

The force acting along a string.

Definition

Thermal conductivity:

The rate of flow of heat across the opposite faces of a meter cube maintained at a difference of 1 K is called the thermal conductivity of the material of the cube.

Definition

Thermometers:

Thermometers are made to measure the temperature of a body of places

Definition

Trigonometric ratios:

The ratios of the slides of a right-angled triangle.

Definition

Translatory motion:

The motion of a body when it moves along a line without rotation.

Definition

Thermal equilibrium

The property of a system is when all parts of the system have the same temperature along with its surrounding.

Definition

Torque:

The capacity of a force to rotate a body.

Definition

Uniform acceleration:

A body has uniform acceleration if it has equal chances in its velocity in equal intervals of time, however small the interval may be.

Definition

Uniform speed:

If the speed of a body does not change with time then its speed is uniform.

Definition

Uniform velocity:

If a body covers equal displacements in equal intervals of time, however small the interval may be, then its velocity is said to be uniform.

Definition

Unlike parallel forces:

Forces that are parallel but have direction opposite to each other.

Definition

Unstable equilibrium:

If a body does not return to its previous position when set free after a slight tilt is said to be in unstable equilibrium.

Definition

Vectors:

Physical quantities which are described by their magnitude and direction are known as vectors.

Definition

Velocity:

We define velocity as the rate of change of displacement or speed in a specific direction.

Definition

Vibratory motion:

The zig-zag motion of the molecules of gases and liquids.

Definition

Watt:

1. The power of a body is one watt which is doing work at the rate of one joule per second.

Definition

Weight:

The weight of a body is the force of gravity acting on it. It is a vector quantity. SI unit of weight is Newton (N).

Definition

Work:

1. Work is said to be done when a force acting on a body moves it in the direction of the force.
• Work = FS
• SI unit of work is the joule (J).
Definition

Young's modulus:

The ratio between stress and tensile strain is called Young's modulus.