You apply the brakes of your car abruptly and your book starts sliding off the front seat. three observers sitting in the car explain this differently. observer a says that the book continued moving and the car accelerated from underneath it. observer b says that the car pushed forward on the book. observer c says that she must be in a noninertial reference frame because the book started moving without any extra objects interacting with it. which of the observers is correct? assume that the car is a frame of reference of all observers.

radiation warms things up temp rises convection currents air circ windy weather

wire in brush may conduct electricity from cell to drill and vice versa electrc shock possible

i think it's 35 meters

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.