A heat pump is a device used to heat something, in this case water. Heat pump takes heat from colder object and transfers it to warmer object. This is opposite to <span>direction of spontaneous heat transfer which from warmer to colder object.
In this problem a room got colder while water got warmer. This is due to work done by heat pump. This is what is described in correct answer c).
a) is not correct because it shows </span>direction of spontaneous heat transfer. It also says that <span>Aleksei’s family purchased a new water heater and in description givne in a) it would mean that water got colder.
b) is not correct because if the </span><span>burning fuel increased the thermal energy in the air it would mean that this room got warmer than rest of house.
d) is not correct because burning fuel does not absorb </span><span>thermal energy. It releases it.</span>
Answer:
1.19cm^3 of glycerine
Explanation:
Let Vo= 150cm^3 for both aluminum and glycerine, using expansion formula:
Volume of spill glycerine = change in volume of glycerine - change in volume of aluminum
Volume of glycerine = coefficient of volume expansion of glycerine * Vo* change in temperature - coefficient of volume expansion of Aluminum*Vo* change temperature
coefficient of volume expansion of aluminum = coefficient of linear expansion of aluminum*3 = 23*10^-6 * 3 = 0.69*10^-4 oC^-1
Change in temperature = 41-23 = 18oC
Volume of glycerine that spill = (5.1*10^-4) - (0.69*10^-4) (150*18) = 4.41*10^-4*2700 = 1.19cm3
Answer:
The thermal conductivity of the wall = 40W/m.C
h = 10 W/m^2.C
Explanation:
The heat conduction equation is given by:
d^2T/ dx^2 + egen/ K = 0
The thermal conductivity of the wall can be calculated using:
K = egen/ 2a = 800/2×10
K = 800/20 = 40W/m.C
Applying energy balance at the wall surface
"qL = "qconv
-K = (dT/dx)L = h (TL - Tinfinity)
The convention heat transfer coefficient will be:
h = -k × (-2aL)/ (TL - Tinfinty)
h = ( 2× 40 × 10 × 0.05) / (30-26)
h = 40/4 = 10W/m^2.C
From the given temperature distribution
t(x) = 10 (L^2-X^2) + 30 = 30°
T(L) = ( L^2- L^2) + 30 = 30°
dT/ dx = -2aL
d^2T/ dx^2 = - 2a
<span>An alpine glacier can change the topography of a mountainous area through Glacial Erosion and Glacial Deposition. Glaciers are agents of erosion, it can pick up and carry large rocks and sediments. In the process, a deep cavity or hole can form when the glacier plucks a big rock from where it passed. Glaciers have shaped many Mountain Ranges and have created distinct landforms by its erosion process. In Glacial Deposition, as glaciers melt, it deposits all that it carried and a landform is developed.</span>
pshyical change is a usually reversible change of a substance, as size or shape: Freezing a liquid is a physical change. Compare chemical change.
internal change is when the movement of the particles increases
specific latent heat is the amount of energy per kg (unit mass) required to change ice to water without change in temperature.
