Temperature and Internal Energy/Time to heat water

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SUMMARY

The discussion focuses on two key problems related to temperature and internal energy in water. The first problem compares the temperature (T) and internal energy (U) of water in a cup versus a swimming pool, with the correct answer being option (b): Tpool is equal to Tcup, and Upool is less than Ucup. The second problem involves calculating the time required to heat 20 kg of water from 20 degrees Celsius to 100 degrees Celsius using a 5 kW heater, with the correct answer being option (a): 32 minutes. Participants are encouraged to apply relevant equations from their textbooks to solve these problems.

PREREQUISITES
  • Understanding of thermodynamics principles, specifically temperature and internal energy.
  • Familiarity with the specific heat capacity of water.
  • Knowledge of power calculations related to heating (P = Q/t).
  • Ability to apply equations from thermodynamics, such as Q = mcΔT.
NEXT STEPS
  • Research the specific heat capacity of water and its implications in heating calculations.
  • Learn about the relationship between power, energy, and time in heating scenarios.
  • Study the laws of thermodynamics, particularly the first law regarding energy conservation.
  • Explore practical applications of thermodynamic equations in real-world heating systems.
USEFUL FOR

Students in physics or engineering, educators teaching thermodynamics, and anyone interested in understanding the principles of heat transfer and energy calculations in fluids.

juanita
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A cup of water is scooped up from a swimming pool of water. Compare the temperature T and the internal energy U of the water, in both the cup and the swimming pool.
a) Tpool is less than Tcup, and the U is the same.
b) Tpool is equal to Tcup, and Upool is less than Ucup.
c) Tpool is equal to Tcup, and Upool is greater than Ucup.
d) Tpool is greater than Tcup, and the U is the same.

A 5 kW heater is used to heat water. How long will it take to heat 20 kg of water from 20 degrees celsius to 100 degrees celsius?
a) 32 minutes
b) 2 minutes
c) 12 minutes
d) 22 minutes

any help would be appreciated, thanks!
 
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Welcome to PF :smile:

What are your thoughts on how to solve the problems? What equations (from your textbook or class lecture) do you think would apply here?
 

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