Q. What will be the unit of time in that system in which the unit of length is metre, unit of mass is kg and unit of force is kg wt?
A) $(9.8)^{2}$sec
B) 9.8 sec
C) $\sqrt{9.8}$ sec
D) $\frac{1}{\sqrt{9.8}}$ sec
Explanation
We know $\lbrack F\rbrack = \lbrack MLT^{- 2}\rbrack$ $T^{2} = \frac{ML}{F} = \frac{1kg \times 1m}{1kg - wt} = \frac{1kg \times 1m}{9.8N}$ $T = \frac{1}{\sqrt{9.8}}$ sec
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.