Q. An electron has a mass of $9.1 \times 10^{- 31}kg.$ It revolves around the nucleus in a circular orbit of radius $0.529 \times 10^{- 10}metre$ at a speed of $2.2 \times 10^{6}m/s.$ The magnitude of its linear momentum in this motion is
A) $1.1 \times 10^{- 34}kg - m/s$
B) $2.0 \times 10^{- 24}kg - m/s$
C) $4.0 \times 10^{- 24}kg - m/s$
D) $4.0 \times 10^{- 31}kg - m/s$
Explanation
(b) Linear momentum $= mv = 9.1 \times 10^{- 31} \times 2.2 \times 10^{6}$
$= 2.0 \times 10^{- 24}kg - m/s$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.