Unit one (1)
1.1 Measurement and Dimensions
1 : physical Quantity :- Those physical Quantity which was some existence and measurable are known as physical quantity. Eg distanc, time , weight , velocity ,work etc
Types of physical Quantity:-
i> Fundamental Quantities :
Those physical quantities which give own meaning it self and depend upon other physical quantities are called fundamental quantities eg : , mass etc.
ii> Derived Quantities:
Those physical quantity which do not give own meaning itself and depend upon other physical quantities eg. Force, work , power etc.
i> Dimensional Formula :-
That arrangement inside the capital bracket contain there fundamental quantities like mass (M) and length (L) and time (T) such arrangement is called dimensional formula( MLT)
Find the Dimensional Formula and dimensions of physical quantity .
i> Length = [L] =
The power contains in mass length and time is called Dimesions. The Dimensions of length in mass is zero on length is one and time is zero.
ii> Mass = [M] = [M1 L0 T0 ]
The Dimension of mass is “1” length and time is “o”
Velocity :- (V) Velocity is Defined as distance travel by the time= d/t= (L/T)
: Dimensional formula === >> Mass = 0 , Length = 1 , Time = -1
iv) Acceleration (α) :- Velocity/ Time = V/T
= [M* L1T-2]
The dimensional of acceleration is
Mass = 0
Length = 1
Time = -2
v) Force (F) = m*a = m*d/t*t
Vii Work :- Distance * force (L*M*L*T-2)= [ ML=-2]
The Dimension of work is
Vii> power (p) =- Work/time
= [ m1l2T-2]/T
The dimension of power is
Mass = 1
Length = 2
Time = -3
Applications of Dimensional Formula
Qno1 : Check the correctness of a given physical equation.
-To explain this statement take an example
Eg. V2 = u2+2as
LHS -V2 = (D/T)2 = [ L/T]2 = [L2T-2]
Therefore : [ M* L2T-2] = LHS
RHS = u2+2as= d2/t2 + 2 [LT-2l]
[L2T-2] + [ L2T-2]
LHS= RHS proved..
Other important Questions and exercise