Ahighway patrol officer uses a device that measures the speed of vehicles by bouncing radar waves off them and measuring the doppler shift. in one such instance, the outgoing waves had a frequency of 100 ghz and the returning echo had a frequency 15 khz higher. assume the officer is facing in the positive direction. what is the velocity of the vehicle? note that there are two doppler shifts in echoes. be certain not to round off until the end of the problem, because the effect is small.

answer: what are you talking about?

explanation:

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.

electric field is a function of 1/r^2

yes, the force per unit charge for a point charge is inverse square law.