1) Um pesquisador adotou uma escala termométrica Y em que, para a temperatura de fusão do gelo, ele estabeleceu o valor 40° Y e, para a temperatura de ebulição da água, ele estabeleceu 120°Y. A) Certo dia, entre as 9 horas da manhã e o meio-dia, a temperatura ambiente variou e chegou a 7,5oC. Qual é o valor dessa variação de temperatura na escala Y?

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.