Question:
A new system of units is proposed in which unit of mass is α kg, unit of length β m and unit of time γ s. How much will 5 J measure in this new system?
Solution:
Let Q be the physical quantity = n1u1 = n2u2
Let M1, L1, T1 and M2,L2,T2 be the units of mass, length, and time for the given two systems.
n2 = n1
[U] = [ML2T2]
M1 = 1 kg
L1 = 1 m
T1 = 1 s
M2 = α kg
L2 = β m
T1 = γ s
Substituting the values we get, n2 = 5γ2/αβ2 J