Question

In a practical unit if the unit of mass becomes double and that of u it of time becomes half, then 8 joules will equal to ....... unit of work.

• A. 8
• B. 4
• C. 1
• D. 10

Answer 1

Answer: (C)

1

$8$ joules of work done can be expressed,as

Work $=8joules=8kg{m}^2/s^2$

where units,

$mass=kg$

$length=m$

$Time=second=s$

Let the new units be $KG,M$ and $S$

According to question ,new mass is double that of initial value.

$KG=2kg$

$M=m$ (Since no change is mentioned)

$S=\frac{s}{2}$

$Work=8kg{m}^2/s^2$

$=8\left(KG/2\right)\times M^2/(2S{)}^2$

$=\frac{8}{8}\left(KG{M}^2/S^2\right)$

$=1$ Joule of work.