Heat Transfer Methods
On this worksheet you will investigate properties of
the three heat transfer methods
Which method of heat transfer involves actual particles circulating from one region to another?
Which heat transfer method can take place without a medium, that is, in a vacuum?
Newton's Law of Cooling allows us to calculate the rate at which the temperature difference between a hot object and the ambient room temperature changes with the passage of time. T
. At time t = 0, the original temperature difference between a hot solid and the ambient room temperature is 57.7 ºC. If the temperature difference drops to half that value in 20.4 seconds, what is the value of the decay constant, k?
0.0340 per second
0.0302 per second
0.0490 per second
0.0294 per second
At what time will the temperature difference equal 17.9ºC?
An incandescent black body has a peak wavelength of 642 nm when its temperature is 4517 Kelvin. What would be the temperature of a second blackbody radiator that has a peak wavelength of 468.66 nm?
Compare the rate at which energy is given off by the second black body in Question #5 which has a peak wavelength of 468.66 nm to the first black body which has a peak wavelength of 642 nm.
1.1 : 1
3.5 : 1
1.9 : 1
1.4 : 1
If two other incandescent solids are at the same temperature, but one has a surface area that is 5 times greater, how would the radiant power of the larger black body compare to the rate at which energy is emitted by the smaller black body?
it would be 5 times greater
it would be 625 times greater
it would be 1.50 times smaller
it would be 25 times greater
One end of a 57.7-cm copper rod (
= 385 W/mK) is placed in 100 grams of cold water at a temperature of 4.08 ºC. The other end is placed in the flame of a bunsen burner at a temperature of 1028 ºC. If the rod has a radius of 0.5 cm, then what is the initial rate at which heat is conducted along the rod?
If a second copper rod has the same length as the rod in Question #8 but has a radius of 0.155 cm, how would the rate of conductivity be changed?
it would decease by a factor of 0.310
it would decease by a factor of 0.0961
it would increase by a factor of 3
it would increase by a factor of 10
it would not change
If a third copper rod has the same radius as the rod in Question #8, but a length of 80.78 cm, how would the rate of conductivity be changed?
it would be 40% as great
it would be 2.5% as great
it would be 16.0% as great
it would be 60% as great
A 350 watt immersion heater is used to heat a cup of water containing 194 grams of water and a piece of ice. The cup is made of styrofoam which is an insulator and does not give up or receive heat. If it takes 3.10 minutes for the heater to bring the contents of the cup from 0ºC to 65ºC, how much ice was originally present? Here are some constants: c
= 2093 J/kgºC, c
=4186 J/kgºC, L
= 334 kJ/kg
Copyright © 1997-2017
Catharine H. Colwell
All rights reserved.