Q. A body of mass $m = 3.513\ kg$ is moving along the $x -$axis with a speed of $5.00\ {ms}^{- 1}.$ The magnitude of its momentum is recorded as
A) $17.6\ kg\ {ms}^{- 1}$
B) $17.565\ kg\ {ms}^{- 1}$
C) $17.56\ kg\ {ms}^{- 1}$
D) $17.57\ kg\ {ms}^{- 1}$
Explanation
Given, $m = 3.513\ kg$ and $v = 5.00\ {ms}^{- 1}$ So, momentum, $p = mv = 17.565$ As the number of significant digits in $m$ is 4 and $v$ is 3, so, $p$ must have 3 significant digits $\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ p = 17.6\ {kgms}^{- 1}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.