Hi everyone! I need some help studying for a test on Static Electricity.
I have a few review questions that I don't know how to do. Below they are numbered and in parenthesis I answered what I think you might have to do to get the answer. Please help me in any way you can. Your help is much appreciated! =)
1. What is the value of a charge of a body that carries 20 excess electrons?
(For number 1, I think that the question asks you to pretend that something is negatively charged by 20 electrons. So I think you take the charge of an electron, which is 1.6 x 10^-19, and multiply it by 20. If you do that, the answer is 3.2 x 10^-18.)
2. Two like charged balloons, placed at a distance of .5 meters, experience a repulsive force of .32 N. What is the force if the distance between the two balloons is doubled?
(For number 2, if you use Coulomb's Law, the equation used to find .32 N was Force = the constant of K multiplied by the product of the charges divided by the square of the distance. Therefore, I think to solve this, you need to double r, which would mean that force is one-fourth of what it originally was. Following that, I think you divide .32 N by 4 and the answer would be .08 N.)
3. What is the force between two small charged spheres that have charges of 2 x 10^-7 and 3 x 10^-7 if the distance of r is 30 cm.
(For number 3, I think you use Force = the constant of K multiplied by the product of the charges divided by the square of the distance again. If you plug in the numbers, you would get 6 x 10^-7. I am almost sure this is right, if you could please plug in the numbers and let me know if this is the answer because for some reason I can never get the right numbers even if I follow the right steps.)
THANK YOU SO MUCH!
Hi everyone. I also broke these up into separate questions because I figured it would be easier to answer that way in case your specialty is one of the questions and not static electricity as a whole.
Thanks to everyone who helps!
all correct., except I wont do the calculations for you.
You're on the right track with your explanations for the first two questions! Let's go through them and confirm your answers:
1. To find the value of the charge of a body that carries 20 excess electrons, you multiply the charge of one electron by the number of excess electrons. The charge of an electron is 1.6 x 10^-19 C, so multiplying it by 20 gives us 3.2 x 10^-18 C. So your answer is correct!
2. For this question, you correctly mentioned Coulomb's Law, which states that the force between two charged objects is directly proportional to the product of their charges and inversely proportional to the square of the distance between them. According to Coulomb's Law, if you double the distance between two charged objects, the force between them becomes one-fourth of what it originally was. So, if the initial force is 0.32 N, doubling the distance would result in a force of 0.08 N. Your answer is correct!
Now, let's move on to question 3:
3. To determine the force between two small charged spheres, you can indeed use Coulomb's Law. Given the charges of the spheres (2 x 10^-7 C and 3 x 10^-7 C) and the distance between them (30 cm = 0.3 m), you can plug these values into the equation:
Force = (K * (q1 * q2)) / (r^2)
where K is the electrostatic constant (9 x 10^9 Nm^2/C^2), q1 and q2 are the charges, and r is the distance between the spheres.
By substituting the given values into the equation, you should get:
Force = (9 x 10^9 * (2 x 10^-7) * (3 x 10^-7)) / (0.3^2)
Calculating this expression results in a force of 6 x 10^-7 N. So your answer is correct! Well done!
Remember, when using formulas, it's essential to substitute the correct values, pay attention to units, and use the appropriate mathematical operations. Keep practicing, and you'll become even more comfortable with these concepts. Good luck with your studying!