Sig Fig Problem: Calculating t with I=3.20A, L=4.2m, etc

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The discussion centers on calculating the thickness (t) using the formula t = ((l*w)*n*q*L)/I with given parameters: I = 3.20 A, L = 4.2 m, cross-section = 0.00220 m, n = 8.85 x 10^28, and e = 1.6 x 10^-19. The calculated value of t is 8.99 x 10^4, but the user is confused about the significant figures in the result. Since both L and e are provided with two significant figures, the final answer must also be expressed to two significant figures, resulting in t = 9.0 x 10^4.

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Tcat
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In this one problem I am given I=3.20A, L=4.2m, cross-section=.00220m, n=8.85*10^28, and e=1.6*10^-19.
I am using an equation that is set up like this to find the t=((l*w)*n*q*L)/I
When I calculate ((0.00220m)^2*(8.85*10^28)(1.6*10^-19)*(4.2))/(3.2) I get 8.99*10^4 and for some reason the sig. figs are wrong! I don't know why?
 
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Since L and e are given only to two significant figures your final answer should also be written to two significant figures.
 

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