How many electrons have been removed from a positively charged electroscope?

AI Thread Summary
To determine how many electrons have been removed from a positively charged electroscope with a net charge of 7.5x10^-11 C, one must divide the net charge by the charge of a single electron, which is 1.6x10^-19 C. This calculation leads to the conclusion that the number of electrons removed is approximately 4.69x10^8. The participants confirm that this method is correct and express understanding of the calculation process. The discussion effectively clarifies the relationship between charge and the number of electrons.
mimictt
Messages
8
Reaction score
0
Hello everyone! I'm having a problem with this question from my book...

How many electrons have been removed from a positively charged electroscope if it has a net charge o 7.5x10^-11 C?

Can someone explain to me how to solve this problem>?
Thank you very much!
 
Physics news on Phys.org


Hello,

What is the charge of a single electron? What about two? What about an arbitrary number call it "x" electrons?
 


What's the charge on each electron?
 


it's 1.6x10^-19 C

so does it mean that 7.5x10^-11/ 1.6x10^-19 is the number of electrons?
 


oh i think i got it! thank you so much!
 


mimictt said:
it's 1.6x10^-19 C

so does it mean that 7.5x10^-11/ 1.6x10^-19 is the number of electrons?

yes!
 
I multiplied the values first without the error limit. Got 19.38. rounded it off to 2 significant figures since the given data has 2 significant figures. So = 19. For error I used the above formula. It comes out about 1.48. Now my question is. Should I write the answer as 19±1.5 (rounding 1.48 to 2 significant figures) OR should I write it as 19±1. So in short, should the error have same number of significant figures as the mean value or should it have the same number of decimal places as...
Thread 'Collision of a bullet on a rod-string system: query'
In this question, I have a question. I am NOT trying to solve it, but it is just a conceptual question. Consider the point on the rod, which connects the string and the rod. My question: just before and after the collision, is ANGULAR momentum CONSERVED about this point? Lets call the point which connects the string and rod as P. Why am I asking this? : it is clear from the scenario that the point of concern, which connects the string and the rod, moves in a circular path due to the string...
Thread 'A cylinder connected to a hanging mass'
Let's declare that for the cylinder, mass = M = 10 kg Radius = R = 4 m For the wall and the floor, Friction coeff = ##\mu## = 0.5 For the hanging mass, mass = m = 11 kg First, we divide the force according to their respective plane (x and y thing, correct me if I'm wrong) and according to which, cylinder or the hanging mass, they're working on. Force on the hanging mass $$mg - T = ma$$ Force(Cylinder) on y $$N_f + f_w - Mg = 0$$ Force(Cylinder) on x $$T + f_f - N_w = Ma$$ There's also...
Back
Top