Question

The nucleus of helium atom contains two protons that are separated by distance $3.0 \times 10^{- 15}$m. The magnitude of the electrostatic force that each proton exerts on the other is.

• A. $20.6N$
• B. $25.6N$
• C. $15.6N$
• D. $12.6N$

Answer 1

Answer: (B)

$25.6N$

Answer 2

: Charge of proton is $q_{p} = 1.6 \times 10^{- 19}C$ Distance between the protons is $r = 3 \times 10^{- 15}m$

The magnitude of electrostatic force between protons is

$F_{e} = \frac{q_{p}q_{p}}{4\pi\varepsilon_{0}r^{2}}$

$= \frac{9 \times 10^{9} \times 1.6 \times 10^{- 19} \times 1.6 \times 10^{- 19}}{(3 \times 10^{- 15})^{2}} = 25.6N$