Three negative point charges lie along a line as shown in the figure. Find the magnitude of the electric field this combination of charges produces at point P, which lies 6.00 cm from the -2.00 μC charge measured perpendicular to the line connecting the three charges. (E = N/C)
The problem: Three negative point charges lie along a line as shown in F i g . E 2 1 . 4 1 . Find the magnitude and direction of the electric field this combination of charges produces at point P P , which lies 6.00 cm from the − − 2.00- μ μ C charge measured perpendicular to the line connecting the three charges. The Illustration: Given: q1 = q2 = -5.00 μC q3 = -2 μC r1 = 10.00 cm = 0.1m r = distance r3 = 6.00 cm = 0.06m Couloumb Constant (k) = 9 ×10 9 kg⋅m 3 ⋅s − 2 ⋅C − 2 The equation to use: Solution The electric field at P due to q1 and q2 is E 1 = E 2 = k(q 1 /r1 2 ) = 9x10 9 x (5x10 -6 / (0.1) 2 = 4.5x10 6 N/C The electric field at P due to q3 is E 3 = k(q 3 /r3 2 ) = 9x10 9 x (2x10 -6 / (0.06) 2 = 5x10 6 N/C cos Θ = 6/10 = 3/5 NET ELECTRIC FIELD E net = 2E 1 (cos Θ ) + E 3 = 2(4.5x10 6 )⅗ ...