A cup of hot coffee sits on your desk. Assume that the thermal energy in the coffee can be converted with an efficiency of 100%% to gravitational potential energy of the coffee-Earth system-enough so that the coffee rises up above the rim of the cup. Let the height of the coffee rise by 3.4 cm. Find the magnitude of the drop in temperature needed to accomplish this energy conversion. Use c = 4180 J/kg⋅C for coffee.

A cup of hot coffee sits on your desk. Assume that the thermal energy in the coffee can be converted with an efficiency of 100%% to gravitational potential energy of the coffee-Earth system-enough so that the coffee rises up above the rim of the cup. Let the height of the coffee rise by 3.4 cm. Find the magnitude of the drop in temperature needed to accomplish this energy conversion. Use c = 4180 J/kg⋅C for coffee.

Physics for Scientists and Engineers: Foundations and Connections

1st Edition

ISBN:9781133939146

Author:Katz, Debora M.

Publisher:Katz, Debora M.

Chapter9: Energy In Nonisolated Systems

Section: Chapter Questions

Problem 42PQ

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