# II Question 37.1

(a) What would a proton’s mass M be if the gravitational force between two protons at rest were to equal the electric force? How does this compare with its actual mass m_p?

(b) What would be the electric force F between two dimes placed at opposite ends of a 10 meter lecture table if the nuclear and electronic charges were unbalanced by 1%? Can you think of some object whose “weight” equals that force? (Assume that a dime is made from 2.5 \times 10^{-3} kg of pure silver.)

(a)

Gravitational force is G\frac{m_p^2}{r^2}.

Electric force is k\frac{m_p^2}{r^2}