Question

Consider an electron and a proton separated by a distance of 4.5 nm. (a) what is the magnitude of the gravitational force between them? 5.1128e-20 incorrect: your answer is incorrect. n (b) what is the magnitude of the electric force between them?

Answer 1

a.) For letter a, we use the law of universal gravitation using the constant G = 6.674×10−11 m3⋅kg−1⋅s−2

Grav. F = G*m1*m2*(1/d^2)

m1 is mass of electron = 9.11 × 10-31 kg
m2 is mass of proton = 1.67 × 10-27 kg
d = 4.5 nm = 4.5 x 10^-9 m

Grav F = 5.01 x 10^-51 N

b.) For letter b, we use the Coulomb's using the constant k = 9×10^9 N

Electric force = k*Q1*Q2*(1/d^2)
Q1 is charge of electron = -1.6 × 10-19 C
Q2 is charge of proton = +1.6 × 10-19 C

Electric force = 1.14 x 10^-11 N