Question 741: Electrostats & Capacitance

Question

Three point charges of magnitude $$5 \mu \mathrm{C}, 0.16 \mu \mathrm{C}$$ and $$0.3 \mu \mathrm{C}$$ are located at the vertices $$A, B, C$$ of a right angled triangle whose sides are $$A B=3 \mathrm{~cm}, B C=3 \sqrt{2} \mathrm{~cm}$$ and $$C A=3 \mathrm{~cm}$$ and point $$A$$ is the right angle corner. Charge at point $$\mathrm{A}$$ experiences ____________ $$\mathrm{N}$$ of electrostatic force due to the other two charges.

Accepted Answer

$${F_{AC}} = {{k(5 	imes 0.3) 	imes {{10}^{ - 12}}} \over {9 	imes {{10}^{ - 4}}}}$$
$${F_{AB}} = {{k(5 	imes 0.16) 	imes {{10}^{ - 12}}} \over {9 	imes {{10}^{ - 4}}}}$$
$${F_{net}} = {{k 	imes {{10}^{ - 12}}} \over {9 	imes {{10}^{ - 4}}}}\sqrt {{{1.5}^2} + {{(0.8)}^2}} $$
$$ = {{{{10}^9} 	imes {{10}^{ - 12}}} \over {{{10}^{ - 4}}}} 	imes 1.7 = 17$$

Electrostats & Capacitance

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