A 1500 W Portable Heater Is Needed to Replace the Heat

question 59

Multiple Choice

A 1500 W portable heater is needed to replace the heat lost through a circular window (radius 25 cm) in the wall of a home. The thermal conductivity for the glass is 0.63 W/mK. The temperature inside the house is 20 °C and outside is −12 °C. What is the thickness of the window?

• A) 0.84 mm
• B) 4.2 mm
• C) 2.6 mm
• D) 0.66 mm

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Definitions:

Face Value

The nominal value or dollar value printed on a security, such as a bond or stock certificate, representing its value at issuance.

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