3. Two charges Q, and D2 are 8.0 crn apart Charge Q1 = 5,0 nC and Q2 = -benc. The
.magnitude of the electric field at point P, 3.9
cm from the midpoint of the line joining Q1
and Q2, is (a)2.9 X 109N/C(b) 2.9 X 10^N/C
(c) 3:6 X 105N/C (490.297kN/clė3.6 X 106N/C

speed of light in vacuum is 300,000 km/s

speed of light in other mediums is given by the expression v = c/n, where c is the speed of light in vacuum and n is the refractive index of medium.

for the first medium v = 200,000 km/s

  so, refractive index of medium = 300000/200000 = 1.5

    1.5 refractive index is usually for glass. so first medium is glass.

for the second medium v = 250,00 km/s

so, refractive index of medium = 300000/250000 = 1.2

    1.2 refractive index is usually for water. so second medium is water.

for the third medium v = 0 km/s

so, refractive index of medium = 300000/0 = ∞

    ∞ refractive index is usually for opaque mediums. so third medium is opaque medium.

no

explanation:

no i dont know how to solve this you should probably try to google the answer