1. If a block of metal has 23 J of energy, and a mass of 20 kg, is sitting in a

Question

1. If a block of metal has 23 J of energy, and a mass of 20 kg, is sitting in a furnace that is kept at 200 degree Celsius. What is the heat capacity of the block?

2. Fire man from the fantastic four is constantly radiation heat. One day he goes to a waste water treatment plant and places his hand on a pipe that is connected to a reservoir 20 meters away. According to the 0th law of thermodynamics; if fire man keeps his hand on that pipe long enough, will the reservoir boil? Why or why not?

3. If a ball of molten steel is places into a vat of ice cold water. Which direction is the energy flowing?

4. You are sitting in the cockpit of a F-22 flying at 47,00 ft. There is a glass of water (2 kg) in your lap that has an energy of 7 J as your flight continues the water’s energy increases from 7 J to 12 J. If it’s initial temperature was 17 degrees Celsius. What is it final temperature?

5. What is the energy of a metal that has a heat capacity of .3 and is heated from 10 degree to 22.7 degrees and has a mass of 4 kg.

Explanation / Answer

1) H = Q/(m(deltaT)) = 23/200*20 = 0.00575 J kg-1 0C-1

2) The zeroth law of thermodynamics states that if two thermodynamic systems are each in thermal equilibrium with a third, then they are in thermal equilibrium with each other.

So hand & pipe AND pipe and reservior will be at equilibrium after infinetly long time, this means reservior will boil.

3) From the ball to water.

4) energy contained in water is due to its heat content, which increased by 5 joules OR 2.5 J per kg. This means temperature increased is 2.5/4.184 = 0.597 oC => final temp. = 17.7 C

5) Energy = heat capacity*mass*change in temp. = 0.3*4*(22.7-10) = 15.24 Joules

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