Question

If the unit of force were kilonewton, that of time millisecond and that of power kilowatt, what would be the units of mass in kg ?

Answer 1

$\left[F\right]=\left[ML{T}^{-2}\right]$ and $\left[P\right]=\left[M{L}^2{T}^{-1}\right]\Rightarrow \frac{P}{F^2}=\frac{T^3}{M}\Rightarrow \left[M\right]=\frac{F^2{T}^3}{P}$

Unit of mass = $\frac{\left({10}^3{)}^2\right({10}^{-3}{)}^3}{\left({10}^3\right)}$ = $1kg$