A balloon rubbed against denim gains a
charge of −2.0 µC.
What is the electric force between the
balloon and the denim when the two are
separated by a distance of 5.0 cm? (Assume that the charges are located at a
point.) The value of the Coulomb constant is
8.98755 × 10
9
N · m2
/C
2
.
Answer in units of N
It says its wrong.
Where did you get 210?
If the balloon gains a charge of -2.0 μC, the denim has to gain a charge of +2.0 μC.
May be they want
F=k•Q1•Q2/r^2 =
=8.98755•10^9•(2•10^-6) •(-2•10^-6) /(0.05)^2 = - 14.4 N
cell
To calculate the electric force between two charges, we can use Coulomb's Law, which states that the electric force between two charges is directly proportional to the product of the charges and inversely proportional to the square of the distance between them.
The formula for Coulomb's Law is:
F = (k * |q1 * q2|) / r^2
where F is the electric force, k is the Coulomb constant, q1 and q2 are the charges, and r is the distance between them.
In this case, the charge of the balloon is -2.0 µC, which we need to convert to coulombs (C). 1 µC is equal to 1 x 10^-6 C, so -2.0 µC = -2.0 x 10^-6 C.
The charge of the denim is not given, so we assume it to be +1.0 C for simplicity.
The distance between the balloon and the denim is 5.0 cm, which we need to convert to meters (m). 1 cm is equal to 0.01 m, so 5.0 cm = 5.0 x 0.01 m = 0.05 m.
Now we can plug these values into the formula:
F = (8.98755 x 10^9 N · m^2 / C^2) * |(-2.0 x 10^-6 C) * (1.0 C)| / (0.05 m)^2
F = (8.98755 x 10^9 N · m^2 / C^2) * |(-2.0 x 10^-6) * (1.0)| / (0.05)^2
F = (8.98755 x 10^9 N · m^2 / C^2) * (2.0 x 10^-6) / (0.05)^2
F = (8.98755 x 2.0 x 10^9 N · m^2 / C^2) / (0.0025)
F = (17.9751 x 10^9 N · m^2 / C^2) / (0.0025)
F = 7.19004 x 10^12 N
Therefore, the electric force between the balloon and the denim, when separated by a distance of 5.0 cm, is approximately 7.19004 x 10^12 N.
F=kQ^2/r^2 =
=8.98755•10^9•(210^-6)^2/0.05^2 = 14.4 N