Coulomb’s Law Practice
Name:
Date:
Class: EGR
Coulomb’s Law: Measures the electrostatic FORCE between two charges.
Formula to calculate electrostatic FORCE: 𝑭
=
(𝒌)(𝒒𝟏 )(𝒒𝟐 )
𝒓𝟐
F = Force
k = 9 x 109 Nm2 / C2
q1 and q2 = charges of particle
r = distance between the particles
1) What is the unit used for measuring electric charge?
a)
b)
c)
d)
Ampere
Farad
Volt
Coulomb
2) What is the unit used for measuring electric force between two charges?
a)
b)
c)
d)
Ampere
Newton
Volt
Coulomb
3) What happens to the force between two charges if the distance between them is increased?
a) The force will remain the same.
b) The force will increase.
c) The force will decrease.
4) What happens to the force between two charges if the distance between them is decreased?
d) The force will remain the same.
e) The force will increase.
f) The force will decrease.
5) What happens to the force between two charges if the magnitude of both charges is doubled?
g) The force will remain the same.
h) The force will increase.
i) The force will decrease.
6) Suppose that two-point charges, each with a charge of +1 Coulomb are separated by a distance of 1 meter.
(a) Will they attract or repel? _______________(b) Determine the magnitude of the electrical force
between them.
7) Two balloons are charged with an identical quantity and type of charge: -0.0025 C. They are held apart at a
separation distance of 8 m. Determine the magnitude of the electrical force of repulsion between them.
8) Two charged particles both with charges of +2.5 x 10-6 C are separated by a distance of 0.0053 m. Find the
magnitudes of the electric force that each particle exerts on the other.
9) Two identical conducting spheres are placed with their centers 0.30 m apart. One is given a charge of +1.2
x 10-6 C and the other is given a charge of -1.8 x 10-6 C.
a) Find the electric force exerted on one sphere by the other.
b) Is this an attractive or repulsive force?
10) A small cork with an excess charge of +6.0 x 10-6 C is placed 0.12m from another cork, which carries a
charge of -4.3 x 10-6 C.
a) What is the magnitude of the electric force between the negative corks?
b) Is this an attractive or repulsive force?
11) Two electrostatic charges of +1.2 x 10-6 C and +5.0 x 10-6 C exert a repulsive force on each other of 175 N.
What is the distance between the two charges? (Look on whiteboard for a hint).
12) Two electrostatic charges of +1 x 10-6 C and +3 x 10-6 C exert a repulsive force on each other of 200 N.
What is the distance between the two charges? (Look on whiteboard for a hint).