Question

In a particular system of unit, if unit of mass becomes half and that of time becomes twice than 10 joule of work will be written as ____ units

Answer 1

joule is the SI unit of workdone / energy.

1 joule means 1 m displacement of object due to 1N force acting on that object.

1 Joule = $1\left(\frac{Kg.m^2}{s^2}\right)$

now, unit of mass becomes half.

e.g., $kg'=\frac{Kg}{2}$

and time becomes twice.

e.g., $sec'=2s$

so, new unit of joule = $\frac{1}{8}\left(kg.m^2}{s^2}$

so, 10J = 10/8 unit

= 1.25 unit

hence, answer will be 1.25 unit