# Homework Help: Find the difference in mass between the charged objects.

1. Jan 24, 2007

### WhoElseoftheBDC

1. The problem statement, all variables and given/known data

Object A is metallic and electrically neutral. It is charged by induction so that it acquires a charge of -4.6 x 10-6 C. Object B is identical to object A and is also electrically neutral. It is charged by induction so that it acquires a charge of +4.6 x 10-6 C. Find the difference in mass between the charged objects.

2. Relevant equations

3. The attempt at a solution

i tried dividing the charge by the charge of one electron/proton which is 1.602x10-9 and then multiplying that by the mass of one electron/proton but i still get the wrong answer!

Last edited by a moderator: May 9, 2015
2. Jan 24, 2007

### Staff: Mentor

How many protons or electrons does it take to make the 4.6uC of charge? What is the mass of a proton and of an electron?

3. Jan 24, 2007

### NoTime

What is the normal electrical charge carrier?
Where did the proton come from?
If C is coulomb, then how many electrons is that?

4. Jan 24, 2007

### WhoElseoftheBDC

i got that one solved by myself guys sorry haha but i do have another...

A tiny ball (mass = 0.015 kg) carries a charge of -20 µC. What electric field (magnitude and direction) is needed to cause the ball to float above the ground?

5. Jan 24, 2007

### Staff: Mentor

6. Jan 24, 2007

### WhoElseoftheBDC

just solved that one too haha...maybe if i keep postin em ill keep gettin em...heres another one...with more detail lol

Consider three identical metal spheres, A, B, and C. Sphere A carries a charge of -6q. Sphere B carries a charge of +5q. Sphere C carries no net charge. Spheres A and B are touched together and then separated. Sphere C is then touched to sphere A and separated from it. Lastly, sphere C is touched to sphere B and separated from it.
what is the charge on sphere c?

this one seems simple but ive tried everything from -1, 1, -5 and 5 i dont understand how to find the answer

7. Jan 25, 2007

### Staff: Mentor

Well, I'm not inclined to help you much more in this thread if you are able to figure out your homework problems on your own. Please consider the PF as a place you go for advanced help, not basic help for your homework. There's a finite amount of bandwidth in any real system, right? You've just wasted some bandwidth, and colored your use of the PF in the future.

Please only post questions that you really are having trouble with. In the real world (after you graduate), time is money. Please only post for help in the future when you are really stuck.