1. Tardigrade
  2. Question
  3. Physics
  4. An ice box made of Styrofoam (Thermal conductivity =0.01 Jm-1s-1K-1) is used to keep liquids cool. It has a total wall area including lid of 0.8 text m2 and wall thickness of 2.0 cm . A bottle of water is placed in the box and filled with ice. If the outside temperature is 30° C the rate of flow of heat into the box is: (in J-s-1 ):

Question Error Report

Thank you for reporting, we will resolve it shortly

Back to Question

Q. An ice box made of Styrofoam (Thermal conductivity $ =0.01\,J{{m}^{-1}}{{s}^{-1}}{{K}^{-1}}) $ is used to keep liquids cool. It has a total wall area including lid of $ 0.8\text{ }{{m}^{2}} $ and wall thickness of $ 2.0\, cm $ . A bottle of water is placed in the box and filled with ice. If the outside temperature is $ 30{}^\circ C $ the rate of flow of heat into the box is : (in $ J-{{s}^{-1}} $ ):

KEAMKEAM 2004

Solution:

$ H=\frac{Q}{t}=\frac{KA({{\theta }_{1}}-{{\theta }_{2}})}{d} $
$ =\frac{0.01\times 0.8(30{}^\circ -0{}^\circ )}{2\times {{10}^{-2}}} $
$ =12\,J-{{s}^{-1}} $