Question

Suppose our scientific community had chosen force ,speed and time as the fundamental mechanical quantities instead of length,mass and time respectively and they chose the respective units if magnitudes $10N$,$100m/s$ and $\frac{1}{100}s$.Then the unit of mass in their system is equivalent to _________ in our system

• A. ${10}^{3}kg$
• B. ${10}^{-3}kg$
• C. $10kg$
• D. ${10}^{-1}kg$

Answer 1

The correct option is B ${10}^{-3}kg$

We know that the force is defined as the rate of change of momentum. It can also be written as:

$F=\frac{mv}{t}$

$m=\frac{Ft}{v}$

$\therefore m=\frac{10N\times \frac{1}{{100}^s}}{100m/s}$

$m={10}^{-3}kg$