I've done this problem at least 85 times what am I doing wrong?

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SUMMARY

The forum discussion centers on a physics problem involving two plastic chips with masses of 4.5x10^-5 kg, separated by 1.5 mm, carrying equal and opposite electrostatic charges. The user calculated the weight of one chip as 0.0441 N using the formula weight = mass x 9.8 m/s². However, a critical error was identified where the mass should be 0.000045 kg instead of 0.0045 kg, leading to incorrect calculations for the charge using Coulomb's law. The correct approach requires recalculating the weight and subsequently the charge to solve the problem accurately.

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Homework Statement


"Two tiny chips of plastic masses 4.5x10^-5 are separated by a distance of 1.5 mm. Suppose that they carry equal and opposite electrostatic charges +/-q. What must the magnitude of the charge be if the electric attraction between them is equal to the weight of one chip?"

Homework Equations


Fe=k*[(qxq)/d^2]
weight= mass (in kg) x 9.8 m/s^2
q=charge
d=distance
k=Coloumb's constant, 8.99x10^9


The Attempt at a Solution


1. First I have calculated the weight of one mass: .0045kg x 9.8 = .0441 N
2. then I set that equal to Coloumb's eq to try to solve for q. I divided k to the left so .0441 / 8.99x10^9 = 4.9054x10^-12.
3. I multiplied 4.9054x10^-12 by d^2 (or .0015^2) and got 1.1x10^-17
4. At this point I have q^2=1.1x10^-17 so I do a square root and get 3.322x10^-9. I have tried to tweek my answer so many times but to no more avail. I have spent almost an hour on this problem (pathetic, I know) but this problem set is due tomorrow and smartwork is being uncooperative. I would really appreciate any help!
 
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welcome to pf!

hi vitaebellaa! welcome to pf! :smile:
vitaebellaa said:
"Two tiny chips of plastic masses 4.5x10^-5
…
1. First I have calculated the weight of one mass: .0045kg x 9.8 = .0441 N

shouldn't that be 0.000045 ? :redface:
 
WOW! 85 times? ... i have to say .. you got patience
 

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