The ground temperature a few meters below the surface is fairly constant throughout the year and is near the average value of the air temperature. In areas in which the air temperature drops very low in the winter, the exterior unit of a heat pump designed for heating is sometimes buried underground in order to use the earth as a thermal reservoir. Why is it worthwhile to bury the heat exchanger, even if the underground unit costs more to purchaseand install than one above ground?

Q: In an isothermal process, 3700 J of work is done by an idealgas. Is this enough information to tell…

A: Work done by an ideal gas in an isothermal process is 3700 J

Q: You are boiling water in a pot on the stove for your herbal tea. There is 0.15kg of water in the pot…

A: Mass of water (M) = 0.15kg Initial state : Liquid at 100°C temperature Final state :  Solid at…

Q: A typical electric refrigerator has a power rating of 600 W, which is the rate (in J/s) at which…

A: Given: The power rating of the refrigerator is 600 W. The heat released into the room is 1000 W.…

Q: What is the change in internal energy of a system that takes in 4.43  106 J of heat, and does 4.50…

A:

Q: A 68 kg cyclist is pedaling down the road at 15 km/h, using a total metabolic power of 480 W. A…

A: The cyclist spends only about 25% of the total metabolic power (P) generated in his body to propel…

Q: When hot-air furnaces are used to heat a house, why is itimportant that there be a vent for air to…

A: A hot-air furnace heats primarily by air convection. For the convective currents to be completely…

Q: A 4-ton air conditioner removes 5.06×107 J (48,000 British thermal units) from a cold environment in…

A: Given: air conditioner removes 5.06×107 J Or 48000 British thermal units Time 1 hr or 3600 sec (a)…

Q: Calculate the net work output of a heat engine following path ABCDA in the figure below.

A:

Q: Calculate the net work output (in ) of a heat engine following path ABCDA in the figure, where v,-…

A:

Q: What are the efficiencies of reversible heat engines operating between (a) the normal freezing and…

A: Given Data: (a) The freezing point of water is: TL=0°C=273 K The boiling point of water is:…

Q: Consider a room that is initially at the outdoor temperature of 20 C. The room contains a 60-W light…

A:

Q: What is the change in internal energy of a system that takes in 4.48 x 106 J of heat, and does 4.50…

A:

Q: A 4-ton air conditioner removes 5.06×107 J (48,000 British thermal units) from a cold environment in…

A: (a)   The energy input of the air conditioner can be calculated as,

Q: A 68 kg cyclist is pedaling down the road at 15 km/h, using a total metabolic power of 480 W. A…

A: The total chemical energy (C.E) (metabolic power) can be converted into thermal energy (Th.E) and…

Q: Initially you have mwater=4.2kg of water at Twater=66 degrees celcius in a insulated container. You…

A: Recall Q=mc∆T Also, principle of calorimetry. Heat lost by hotter body=heat gained by colder body

Q: Imagine that a hypothetical life form is discovered on our moon and transported to Earth. On a hot…

A: The heat of vaporization of the extraterrestrial life form = 167 cal/g. Mass of the sweat lost, m =…

Q: A system does 1.95 × 108 J of work while 7.5 × 108 J of heat is transferred from the system to the…

A: Given data:  Work done by the system (W) = 1.95×108 J Heat transferred from the system to the…

Q: What is the maximum possible coeffcient of performance of a heat pump that brings energy from…

A: The relation between temperature in kelvin and the temperature in Celsius is: Convert the…

Q: During a bout with the flu an 80 kg man ran a fever of 39 degreees Celsius instead of normal body…

A: Mass of man,(m)=80 kg -----(1) [Given] Specific heat of the water,(c)=4190 J/kg-oC -----(2)…

Q: You are boiling water in a pot on the stove for your tea. Being the brilliant scientist you are, you…

A: Given. The 0.1 kg of water in a pot is boiling at 100 degrees celsius. In the process of boiling the…

Q: *101. ao ssm An ideal, or Carnot, heat pump is used to heat a house to a temperature of 294 K (21…

A:

Q: Consider a room that is initially at the outdoor temperature of 20°C. The room contains a 40-W…

A: The energy in the room will be due to the lightbulb, a110-W TV set, a 300-W refrigerator, and a…

Q: What is wrong with the claim that a cyclical heat engine does 4.00 kJ of work on an input of 24.0 kJ…

A: Energy conservation law states that Energy can never be created or destroyed, it can only be…

Q: In a closed system, volume changes from 1.5m³ to 7.5m³ and heat addition is 200kJ. Calculate the…

A:

Q: A Carnot refrigerator extracts heat from a freezer at -5 degree C and exhausts it at 25 degree C .…

A: Convert the temperature from degree centigrade to Kelvin. And

Q: Imagine that a hypothetical life form is discovered on our moon and transported to Eirth. On a hot…

A: Extra terrestrial :Heat lost = Mass * latent heat of vapourisation  = 339 cal/gm * 259 gm = 87801…

Q: A typical electric refrigerator has a power rating of 400 W, which is the rate (in J/s) at which…

A: The expression for find heat from the cold reservoir is W=Qh-QlQl=W-Qh

Q: It is important for the body to be able to cool itself even during moderate exercise. Suppose a 70kg…

A:

Q: What is the change in the internal energy of the system if 400 J of heat is added to the system and…

A: Heat added to system = 400 Joules  Work done by the system = 2300 Joules

Q: On a warm Summer day, a student turns on the fan in his room in the morning and leaves it running.…

A: His room will be warmer since the fan does not cool the air; instead, it cools you by draining sweat…

Q: It is important for the body to be able to cool itself even during moderate exercise. Suppose a 70kg…

A: Given: Man's mass, m=70 kg Time, t=30 min=30×60=1800 sec Power, P=1000 W

Q: What is the maximum efficiency of a heat engine operating between 68oF and 273 kelvins, the…

A: temperature T_1 =68 F =293.15Ktemperature T_2 =273 K   the maximum efficiency of a heat engine…

Q: A Carnot air conditioner takes energy from the thermal energy of a room at 70 F and transfers it as…

A: The temperature are given in Fahrenheit. Convert these temperatures into Kelvin.

Q: A Carnot engine performs work at the rate of 450 kW while using 950 kcal of heat per second. If the…

A:

Q: Questions 123 – 125 relate to a heat engine which uses heat to do 50 J of work, and then exhausts…

A: Given: The work done is 50 J. The heat exhaust of energy into cold reservoir is 100 J.

Q: What is the change in the internal energy of the system if 4000 J of heat is added to the system and…

A: Given  Heat added Q=4000J Work done W=2300J

Q: Is the efficiency of a heat engine more in hilly areas than in the plains?

A: Heat engine is a device which performs work by taking heat from a hot source and rejecting heat to…

Q: An inventor claims to have developed a heat pump that produces a 200-kW heating effect for a 293 K…

A: The coefficient of performance of the heat pump is

Q: Is it impossible to convert the heat from a single source into work without any other effect? How?

A: According to the Kelvin statement in the second law of thermodynamics , it is not possible  to…

Q: What is the change in internal energy (in J) of a system that does 4.50 ✕ 105 J of work while 3.00 ✕…

A:

Q: 14. Calculate the net work output of a heat engine following path ABCDA in the figure below. P (10°…

A:

Q: A student living in a 3-m * 4-m * 4-m dormitory room turns on her 100-W fan before she leaves the…

A: Given Volume of Room V=3m x 4m x 4mPower of fan P=100 WTotal time t=8 nInitial pressure P=100…

Q: A total of a 185 J of work is done on a gaseous refrigerant as it under goes compression, If the…

A: Given data The amount of total work done on the gas is W=-185 J. The increase in internal energy of…

Q: How much work in kJ is necessary to compress air in an insulated cylinder from 0.215 m to 0.035 m?…

A: To solve this we generally make a few necessary assumptions. They are: The gas is ideal gas It is…

Q: Can you warm a kitchen in winter by leaving the ovendoor open? Can you cool the kitchen on a hot…

A: The First Law of Thermodynamics states that the heat transferred between a source of higher…

Q: What is the change in internal energy (in J) of a system that does 4.50 ✕ 105 J of work while 3.40 ✕…

A:

First law of Thermodynamics

The word thermodynamics consists of two words: thermo- and dynamics. Dynamics means the study of motion. The field of thermodynamics is all about the study of the movement of heat. In a more meaningful way, it is stated as the study of the transfer of energy. Energy transfer is something that we encounter in day-to-day life. Automobiles, chemical reactions, refrigerators, and power generators work on the basis of thermodynamic principles.