Water is pumped from a reservoir to a tank suspended 12 m above the reservoir. The water flows through the same size pipe throug
hout the process. Both the reservoir and the tank are open to the atmosphere. If friction in the pipes consumes 20% of the pump energy, determine the mass flow of water if a 2 hp pump is used. Assume the liquid water has a density of 1 g/cm3
1 answer:
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Answer:
- <u><em>c. The copper will get hotter than the aluminum.</em></u>
Explanation:
The <em>energy due to heat flow</em>, i.e. the heat energy, is proportional to the product of the mass, the <em>specific heat capacity</em>, and the change in <em>temperature</em>:
From which you obtain:
That equation tells that the change in temperature is inversely related to the product of the mass and the specific heat.
In the problem, the masses of the samples of copper and aluminum are equal (<em>5.00g</em>) and both samples receive <em>equal amounts of energy due to heat flow</em>, thus the only difference is the <em>specific heat capacity</em> of each sample.
From the above stated relationship between the change in temperature, the heat, the mass, and the specific heat capacity, under the assumption of all the other conditions equal (heat energy and mass), the higher the specific heat capacity the lower the change in temperature, and the lower the specific heat capacity the greater the change in temperature.
The heat capacity of copper (0.09 cal/g°C) is lower than the specific heat capacity of aluminum is (0.22 cal/g°C), thus the increase in temeperature of the copper sample will be greater than that of the aluminum sample. This means that <em>the copper will get hotter than the aluminum (option c.)</em>