Question

Name of 15 physical quantites

Answer 1

Scalar :

The Physical quantities which have only magnitude but no direction, are known as scalar quantities.
For example :- length, Distance, Area, Time etc.

Vector :

The physical quantities which have both direction and magnitude, are known as vector quantities. it is represented with an arrow (→) .

For example:- velocity , Force, Acceleration, momentum and weight .

Motion :
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A body is said to be in motion when it changes it's position with respect to it's surrounding objects.

S.I Unit :- m/s

Distance :
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Distance travelled by a body is the actual length of the path covered by a moving body irrespective of the direction in which the body travels.

S.I unit :- cm, m

Displacement :
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The shortest distance between the initial position and final position of the body, along with direction is known as it's Displacement.

S.I unit :- cm, m

Speed :
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The Distance travelled by a body per unit time is called the speed of a body.

Speed = Distance/ time , V = S/ t

S.I unit :- cm/s, m/s

Velocity :
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The Distance travelled by a body per unit time in a given direction is known as Velocity.

Velocity = Distance travelled in a given direction/ Time Taken

S.I unit :- cm/s, m/s

Acceleration :
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The rate of change of velocity of a body is known as acceleration.

Acceleration= change in velocity/Time taken for change.

a = v - u/t where, v = final velocity , u = initial velocity , t = time .

S.I unit :- cm/s² , m/s²

Force :
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It is the push or pull that produces or tends to change the speed and direction of moving body, or the shape of a body .

S.I unit :- Newton (N)

Momentum :
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The momentum of a body is defined as the product of it's mass and velocity,

Momentum = Mass × velocity

Or, M = m × v

S.I unit :- kg m/s

Mass :
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The mass of a body is the quantity of matter or material contained in it. It is always constant and does not change from place to place.

S.I unit :- gm, kg

Weight :
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The force by which the body is attracted towards the centre of the earth is called weight of the body. The weight of the body varies from place to place on the Earth. my

W = mg.
Weight of 1 kg mass = 9.8 Newton's

S.I unit :- Newton (N)

Work :
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Work is said to be done when a force acting on a body produces displacement in it in the direction of force.

W = F × S

S.I unit :- Nm or Joule (J)

Power :
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The rate of doing work is called power.

power = work/ time, 1 watt = 1 joule/ 1 sec

or, It is also defined as the rate of supplying energy :

P = E/ t

1 horse power ( H.P) = 76 watt.
1 kilo watt ( K.W) = 1000 W = 10³ W
1 mega watt ( M.W) = 10^6 W

S.I unit :- J/s , Watt

Energy :
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The ability of doing work is called energy.

i.e:, The amount of energy possessed by a body = The amount of workdone.

Commercial unit of Electrical energy is kilowatt (kWh)

1 kWh = 3.6 × 10 ^ 6 J.
and 1 unit = 1 KWh = 3.6 ×10 ^ 6 J

S.I unit :- J


Heat :
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It is an agent that produces a sensation of warmth in us. It is also a form of energy.

S.I unit :- cal, k cal , J


Gravity :
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It is the force of attraction which exists between any two objects of the universe.

S.I unit :- m/s²