Question Details

If velocity (V), force (F) and energy (E) are taken as fundamental units, then dimensional formula for mass will be

Options

A

V⁻²F⁰E

B

V⁰FE²

C

VF⁻²E⁰

D

V⁻²F⁰E

Correct Answer :

V⁻²F⁰E

Solution :

The correct option is V⁻²F⁰E.

To find the dimensional formula for mass (M) in terms of velocity (V), force (F), and energy (E) as fundamental units, we can express mass as a product of powers of these quantities:
M=kVaFbEc
where k is a dimensionless constant, and a, b, and c are the exponents we need to determine.

First, let's write down the dimensional formulas of the fundamental quantities in the standard MLT system:
1. Mass: [M]=M1L0T0
2. Velocity: [V]=LT-1
3. Force: [F]=MLT-2
4. Energy: [E]=ML2T-2

Substitute these dimensional formulas into the relation:
[M]=[V]a[F]b[E]c
M1L0T0=(LT-1)a(MLT-2)b(ML2T-2)c
Simplifying the right-hand side by grouping the powers of M, L, and T:
M1L0T0=Mb+cLa+b+2cT-a-2b-2c

By comparing the exponents of M, L, and T on both sides, we get three simultaneous equations:
For M: b+c=1 --- (Equation 1)
For L: a+b+2c=0 --- (Equation 2)
For T: -a-2b-2c=0 --- (Equation 3)

Let's solve these equations:
From Equation 3, we can express a in terms of b and c:
a=-2b-2c
Substitute this expression for a into Equation 2:
(-2b-2c)+b+2c=0
-b=0b=0

Substitute b=0 into Equation 1:
0+c=1c=1

Now, substitute the values of b and c back to find a:
a=-2(0)-2(1)=-2

Therefore, the values are:
a=-2
b=0
c=1

Substituting these values back into the dimensional relation gives:
[Mass]=V-2F0E

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