A7-kg cube of copper (ccu = 386 j/kg-k) has a temperature of 750 k. it is dropped into a bucket containing 5.5 kg of water (cwater = 4186 j/kg-k) with an initial temperature of 293 k. let's try this again, but this time add just the minimum amount of water needed to lower the temperature of the copper to 373 k. in other words, we start with the cube of copper at 750 k and we only add enough water at 293 k so that it completely evaporates by the time the copper reaches 373 k. assume the resulting water vapor remaining at 373 k. how much water do we need ?

when heated, the valance electrons increased their speed and transferred the heat from electron to electron.   i just took the test.

first thing first of the answer is with technology. second thing second thing is that the big bang theory did not happened u see they say it did but what they dont realize is that like dinasures are still a round they might deny it but they and look at these 12 foot human skelteons they find lets see didnt the bible say something about giants. hope this peace.

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.