1.) Two positive charges of 4.3 mC each are separated by 0.25 m.
What is the size and type of force between the two charges? Help
2.) A positive charge of 1.32 x 10-4 C and a negative charge of 9.8 mC
are 0.015 m apart. What is the size and type of force between them? H
3.) Two electrons in an atom are separated by 1.5 x 10-10 m , the typical size
of an atom. What is the size and type of force between them? H
4.) A negative charge of 4.7 mC exerts a repulsive force of 51.0 N on a 2nd charge
0.062 m away. What is the size and polarity (pos or neg) of the 2nd charge? H
5.) A negative charge of 9.3 x 10-5 C exerts an attractive force of 37.4 N when
placed 0.080 m away from a 2nd charge. Find size and polarity of 2nd charge. H
6.) Two positive charges of 3.0 mC exert a repulsive force of 2.0 N on each other.
By what distance are they separated? H
7.) Two charges q1 and q2 are separated by a distance, d and exert a force, F1
on each other. What new force (F2) will exist if:
a) q1 is doubled. H d) d is doubled. H
b) q1 is doubled and q2 is tripled. H e) d is tripled. H
c) q1 is cut in half. H f) q2 is doubled and d is cut in half. H
8.) a) How many electrons are there in 1 C ? H
b) How many excess electrons are on a ball with a charge of -5.26 x 10-17 C ? H
c) How many excess protons are on a ball with a charge of 7.29 x 10-12 C ? H
9.) How many coulombs of negative charge does a 5 gram nickel coin have?
[takes 3 steps; do a) , b) and c) to get answer, don't round off until part c]
a) Find the number of atoms in a nickel.
Its mass is 5 g and nickel has 6.02 x 1023 atoms / 58 g. H
b) Find the number of electrons in the coin. There are 28 electrons / atom. H
c) Find how many coulombs of negative charge in a nickel. 1.6 x 10-19 C / 1 e- H
10.) A lightning bolt transfers 35 C to Earth. How many electrons are transferred? H
