In: Physics
Three point charges are on the x-axis: q1 at the origin, q2 at 3 m, and q3 at 7 m.
A) Find the potential at the point (0, 4 m) if q1 = q2 = q3 = 2 µC. The Coulomb constant is 8.99 × 109 N · m2 /C 2 Answer in units of kV.
B) Find the potential at the point (0, 4 m) if q1 = q2 = 2 µC and q3 = −2 µC . Answer in units of kV.
C) Find the potential at the point (0, 4 m) if q1 = q3 = 2 µC and q2 = −2 µC . Answer in units of kV.
r1 = 4 m
r2 = sqrt(3^2+4^2) = 5 m
r3 = sqrt(7^2+4^2) = 8.1 m
A)
potential due to q1 , V1 = k*q1/r1 = 8.99*10^9*2*10^-6/4 = 4.495
KV
potential due to q2 , V2 = k*q2/r2 = 8.99*10^9*2*10^-6/5 = 3.596 KV
potential due to q3 , V3 = k*q3/r3 = 8.99*10^9*2*10^-6/8.1 = 2.22
KV
net potential V = V1 + V2 + V3 = 10.311 kV
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(B)
potential due to q1 , V1 = k*q1/r1 = 8.99*10^9*2*10^-6/4 = 4.495 KV
potential due to q2 , V2 = k*q2/r2 = 8.99*10^9*2*10^-6/5 = 3.596 KV
potential due to q3 , V3 = k*q3/r3 = -8.99*10^9*2*10^-6/8.1 = -2.22
KV
net potential V = V1 + V2 + V3 = 5.871 kV
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C)
potential due to q1 , V1 = k*q1/r1 = 8.99*10^9*2*10^-6/4 = 4.495 KV
potential due to q2 , V2 = k*q2/r2 = -8.99*10^9*2*10^-6/5 = -3.596 KV
potential due to q3 , V3 = k*q3/r3 = 8.99*10^9*2*10^-6/8.1 = 2.22
KV
net potential V = V1 + V2 + V3 = 3.119 kV