Apot of water is boiling under one atmosphere of pressure. assume that heat enters the pot only through its bottom, which is copper and rests on a heating element. in two minutes, the mass of water boiled away is m = 3.5 kg. the radius of the pot bottom is r = 5.5 cm and the thickness is l = 2.0 mm. what is the temperature of the heating element in contact with the pot?

if the thermos has a vacuum innner, then heat through conv currents and conduction are reduced = vacuum flask

true tan speed = ang vel x radius

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.

490 n

f=125n a=2.5m/s2