Question

In 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. $64$

Answer 1

The correct option is D $64$

The unit of work is $kg{m}^2/s^2$.

$8Joule=\frac{8M{L}^2}{T^2}$

$=\frac{8\left(1kg\right){\left(1m\right)}^2}{{\left(1s\right)}^2}$

On doubling the unit of mass and unit of time is halved:

$=\frac{8\left(2unitofmass\right){\left(1m\right)}^2}{{\left(\frac{1}{2}unitoftime\right)}^2}$

$=\frac{8\times 2}{{\left(\frac{1}{2}\right)}^2}unitsofwork=64unitsofwork.$