Four identical metallic objects carry the following charges: +1.46, +6.39, -4.06, and -9.94C. The objects are brought simultaneously into contact, so that each touches the others. Then they are separated. (a) What is the final charge on each object? (b) How many electrons (or protons) make up the final charge on each object?
I know for (a) you just add them and divide by the number of them, so four. But I can't figure out the last one. I thought you take what you get from (a) and divide by 1.6x10^-19, but for some reason I cannot get it right!
To determine the final charge on each object, you are correct in thinking that you need to add up the charges on all four objects and then divide by four, since they are identical. Thus, the final charge on each object would be:
(1.46 + 6.39 - 4.06 - 9.94) C / 4 = -0.5375 C
Now, to find the number of electrons or protons that make up this final charge, we can use the elementary charge, e = 1.6x10^-19 C.
To calculate the number of charges, we divide the final charge by the elementary charge:
-0.5375 C / (1.6x10^-19 C) ≈ -3.358x10^18
Note that we should take the absolute value since we are interested in the magnitude of the charge, rather than its sign.
Hence, the number of protons or electrons making up the final charge is approximately 3.358x10^18 for each metallic object.