How much heat will flow Thermodynamics

In summary, to find the amount of heat flowing through a 2m X 2m section of concrete in 30 minutes, with a thickness of 20 cm and temperature difference of 31°C, the formula Q/t = (kA/L) ΔT can be used. However, it is necessary to convert the temperatures to Kelvin before plugging them into the equation.
  • #1
hsphysics2
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Homework Statement



How much heat will flow in 30 minutes through a 2m X 2m section of concrete (k= 8.36 x 10^-1 J/s m *C) 20 cm thick if the inside temperature if 21*C and the outside temperature is -10*C?


Homework Equations



Not sure but Q/t= {(kA/L} Tkelvin or Q/t= εσAT^4kelvin



The Attempt at a Solution



I did not attempt the solution because i have no idea what formula to use or how to approach a problem like this
 
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  • #2
hsphysics2 said:

Homework Statement



How much heat will flow in 30 minutes through a 2m X 2m section of concrete (k= 8.36 x 10^-1 J/s m *C) 20 cm thick if the inside temperature if 21*C and the outside temperature is -10*C?


Homework Equations



Not sure but Q/t= {(kA/L} Tkelvin or Q/t= εσAT^4kelvin



The Attempt at a Solution



I did not attempt the solution because i have no idea what formula to use or how to approach a problem like this
Your first equation is the one to use, but you should have a ΔT, rather than a Tkelvin. This is a heat conduction problem.
 

1. How does thermodynamics determine the amount of heat that will flow?

Thermodynamics uses the laws of energy conservation and entropy to determine the amount of heat that will flow between two objects. The direction of heat flow is always from a higher temperature object to a lower temperature object.

2. What factors affect the amount of heat that will flow?

The amount of heat that will flow is affected by the temperature difference between the two objects, the thermal conductivity of the materials, and the surface area of the objects in contact.

3. Can the amount of heat flow be reversed?

Yes, according to the second law of thermodynamics, heat can flow from a colder object to a hotter object, but this will require an external source of energy, such as a heat pump or refrigerator.

4. How is the amount of heat flow measured?

The amount of heat flow is typically measured in units of joules (J) or calories (cal). These units are a measure of energy and can be converted to other units, such as kilowatt-hours (kWh) for larger amounts of heat.

5. How can the amount of heat flow be controlled?

The amount of heat flow can be controlled by changing the temperature difference between the two objects, using insulating materials to reduce heat transfer, or by adjusting the surface area of the objects in contact. Heat flow can also be controlled by regulating the flow of a fluid, such as water, in a system.

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