Heating Water by Shaking: Physics Problem Solved!

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SUMMARY

The discussion centers on a physics problem involving heating water by shaking a thermos flask. The physicist uses 380 cm3 of water at 58°F, shaking it 32 times per minute with each shake dropping the water 1.15 ft. To determine how long he must shake the flask to boil the water, participants suggest calculating the mass of the water, using the specific heat capacity of water (4.186 J/(g*K)), and finding the total energy required to reach the boiling point. The energy generated per shake is also a critical factor in solving this problem.

PREREQUISITES
  • Understanding of specific heat capacity, particularly for water (4.186 J/(g*K))
  • Knowledge of energy transfer principles in physics
  • Ability to perform unit conversions and calculations involving mass and energy
  • Familiarity with basic thermodynamics concepts
NEXT STEPS
  • Calculate the mass of 380 cm3 of water using density
  • Learn how to compute energy required to raise the temperature of water to its boiling point
  • Determine energy generated per shake based on the height of the drop and the number of shakes
  • Explore the implications of thermal energy loss in practical scenarios
USEFUL FOR

This discussion is beneficial for physics students, educators, and anyone interested in thermodynamics and energy transfer methods. It provides insights into practical applications of physics principles in everyday situations.

hatingphysics
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A physicist, upon awaking one morning to find his stove out of order, decides to boil the water for his wife's coffee by shaking it in a thermos flask. Suppose that he uses 380 cm3 of tap water at 58°F, that the water falls 1.15 ft each shake, and that the physicist completes 32 shakes each minute. Neglecting any loss of thermal energy by the flask, how long must he shake the flask before the water boils?

Could anyone give me alittle help as to what equation to
use for this problem?
 
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okay, assuming no thermal or mechanical losses, all of the the energy transferred from this process should be transferred into heat for the water.
Assume a constant density, find the mass, you know c , you know a specified delta T. Remember your units here. Your usual Heat capacity that you find will be in J/(g*K). for water we know this to be 4.186. Find Q. This will be how much energy will have to be converted right? You can calculate how much energy is generated/shake. The rest should be pretty easy.
 
I'm working on this problem too. I just was given different numbers. I have the heat required to reach the boiling point in the water as well as how much heat per shake is happening (J/shake), but I'm stuck here.
 

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