Q.
The nucleus of helium atom contains two protons that are separated by distance 3.0×10−15m. The magnitude of the electrostatic force that each proton exerts on the other is
Charge of proton is qp=1.6×10−19C
Distance between the protons is, r=3×10−15m
The magnitude of electrostatic force between protons is Fe=4πε0r2qpqp =(3×10−15)29×109×1.6×10−19×1.6×10−19 =25.6N