Q. Two free protons are separated by a distance of 1 $\mathring{\mathrm{A}}.\ $If one proton is kept at least and the other is released, the kinetic energy of second proton when at infinite sparation is
A) $23.0 \times 10^{- 19}$ J
B) $11.5 \times 10^{- 19}$ J
C) $2.3 \times 10^{- 19}$ J
D) Zero
Explanation
(b) Energy of second proton = PE of the system
$= \frac{1}{4\pi\varepsilon_{0}}\frac{q_{1}q_{2}}{r}$
$= 9 \times 10^{9} \times \frac{1.6 \times 10^{- 19} \times 1.6 \times 10^{- 19}}{1 \times 10^{- 10}}$
$= 23.0 \times 10^{- 19}\ $J
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.