Question

3) Three point charges, -2.00 μC, +4.00 μC and + 6.00 μC. are located along the x-axis as shown in the figure. What is the electric potential (relative to infinity) at point P due to these charges? 

4) The three point charges shown in the figure form an equilateral triangle with sides 4.9 cm long. What is the electric potential (relative to infinity) at the point indicated with the dot, which is equidistant from all three charges? Assume that the numbers in the figure are all accurate to two significant figures. 

Answer 1

part 3 )

V = kq/r

electric potential is scalar quantity so we can add them

V = kq1/r1 + kq2/r2 + kq3/r3

r1 = r3 = 0.2828 m

r2 = 0.2 m

V = k(q1/r1 + q2/r2 + q3/r3)

V = q1 = -2 uC

q2 = 4 uc

q3 = 6 uc

k = 9x 10^9

V = 307298.44 V

V = 307 kV

part 4 )

V = kq1/r1 + kq2/r2 + kq3/r3

V = r1 = r2 = r3 they are from equi distance

V = k/r ( q1 + q2 + q3 )

q1 = +2 nc

q2 = -1nc

q3 = -1 nc

V = k/r(2 -1 -1)

V = 0 V