Think back to coulomb's law. two coins with identical charges are placed on a lab table 1.35 m apart.

a. if each coin experiences a force of 2.0 n because of the presence of the other coin, calculate the charge on each coin.

The Coulomb’s law is expressed mathematically as:

F = k * q1 * q2 / d^2

Where,

F = force of attraction between 2 particles = 2.0 N

k = Coulomb’s constant = 8.988 * 10^9 N m^2 / C^2

q = charge of the particle

d = distance between the 2 particles = 1.35 m

Since the two coins have identical charges therefore q1 = q2 = q

F = k * q^2 / d^2

2.0 N = (8.988 * 10^9 N m^2 / C^2) * q^2 / (1.35 m) ^2

q = 2.01 * 10^-5 C

Therefore each coins have charges equivalent to 2.01 * 10^-5 C.