In a particular system of unit, if the . . .

Question : In a particular system of unit, if the unit of mass becomes twice and that of time becomes half, then 8 joules will be written as ___________ units of work. 

(A) 16
(B) 1
(C) 4
(D) 64

Doubt by Divya 

Solution : 


M'=2M
L=L

T'=T/2



We know

8 J = 8 kgm²/s²
x units of work = 8×2kgm²/(1/2)s²

x units of work = 8×2kgm²/(1/2)s²
x units of work = 64 kgm²s²


Hence, 8 J of work can be written as 64 units of work.