# Physics Terms 2

## Terms

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Acceleration due to gravity
The acceleration produced in a body due to the earth's attraction is called acceleration due to gravity. It is denoted by the letter g. Its SI unit is m/s². On the surface of the earth, its average value is 9.8m/s².
Acceleration
The rate of change of velocity of a moving object
Amp[Ampere]
Unit of electric current. It is equivalent to coulomb/sec.
Amplitude [of waves]
The maximum displacement of particles of the medium from their mean positions during the propagation of a wave
Angle of incidence
Angle of an incident (arriving) ray or particle to a surface; measured from a line perpendicular to the surface (the normal)
Angle of reflection
Angle of a reflected ray or particle from a surface; measured from a line perpendicular to the surface (the normal)
6.02 x 10^23
Centripetal force
The force required to pull an object out of its natural straight-line path and into a circular path
Coulomb
Unit used to measure quantity of electric charge
Diffraction
The bending of light around the edge of an opaque object
Doppler effect
An apparent shift in the frequency of sound or light due to relative motion between the source of the sound or light and the observer
First law of motion
Every object remains at rest or in a state of uniform straight-line motion unless acted on by an unbalanced force
Frequency (of waves)
The number of waves produced per second is called its frequency.[Hz]
Index of refraction
The ratio of the speed of light in a vacuum to the speed of light in a material
Inertia
The property of matter that causes it to resist any change in its state of rest or of uniform motion.
Joule
Metric unit used to measure work and energy; can also be used to measure heat; equivalent to newton-meter
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
Newton
A unit of force defined as kg.m/sec^2
Newton's second law of motion
The rate of change of momentum is equal to the force applied OR the force acting on a body is directly proportional to the product of its mass and acceleration produced by the force in the body.
Newton's third law of motion
To every action there is an equal and opposite reaction
Ohm
Unit of resistance; equivalent to volts/amps
Power
The rate of doing work is called power. Power is a scalar quantity. The SI unit of power is Watt ( 1 W = 1 J/sec)
Refraction
A change in the direction of travel of light, sound, or other waves crossing a boundary
Scalar Quantity
is described completely by its magnitude
Volt
Unit of potential difference equivalent to joules/coulomb
Watt
Metric unit for power; equivalent to joule/sec
Work
Work is done when a force acting on a body displaces it. Work is a scalar quantity. The SI unit for work is Joule

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