A woman tells an engineer that she stands in front of an open refrigerator, she feels cooler. But the engineer tells that it is impossible because the fan of the refrigerator is not running and this is only a psychological effect. Which side do you take ? Why ? b) Hot air at 50 C does not cause a lethal burn on our skin, but water with the same temperature is dangerous and it can burn our skin. Explain the reason?

A woman tells an engineer that she stands in front of an open refrigerator, she feels cooler. But the engineer tells that it is impossible because the fan of the refrigerator is not running and this is only a psychological effect. Which side do you take ? Why ? b) Hot air at 50 C does not cause a lethal burn on our skin, but water with the same temperature is dangerous and it can burn our skin. Explain the reason?

Refrigeration and Air Conditioning Technology (MindTap Course List)

8th Edition

ISBN:9781305578296

Author:John Tomczyk, Eugene Silberstein, Bill Whitman, Bill Johnson

Publisher:John Tomczyk, Eugene Silberstein, Bill Whitman, Bill Johnson

Chapter9: Refrigerant And Oil Chemistry And Management-recovery, Recycling,

Section: Chapter Questions

Problem 5RQ: An increase in the natural greenhouse effect that leads to heating of the earth is called _____.

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a) A woman tells an engineer that she stands in front of an open refrigerator, she feels cooler. But the engineer tells that it is impossible because the fan of the refrigerator is not running and this is only a psychological effect. Which side do you take ? Why ? b) Hot air at 50 C does not cause a lethal burn on our skin, but water with the same temperature is dangerous and it can burn our skin. Explain the reason? Any SAME answer from the internet sources or your friends will give you ZERO (0) point. *
Water melts as temp increases because : - chemical potential of the liquid is lower than that of gas - liquid and solid form eutectic mixture -chemical potential of the liquid and solid become equal
It is a heat transfer question. Please briefly explain.
It is a heat transfer question.
MOVIng to another question will save this response. Question 1 Estimate the size of cooling equipment (in kW), that is needed for a new post office building in middle America that is 45.1 m by 61.7 m by 4.95 m high.
Please help! Thank u! 3. Consider the following systems. a) What is the heat capacity of a system consisting of a 0.870-kg brass cup filled with 0.0500 kg of water? Specific heats of brass and water at 1.00 atm and 20.0°C are 0.384 kJ/kg•K and 4.186 kJ/kg/K respectively. b) What is the heat capacity of a system consisting of 8.10 kg of water in a 0.310-kg aluminum bucket? Specific heats of aluminum and water at 1.00 atm and 20.0°C are 0.900 kJ/kg-K and 4.186 kJ/kg:K respectively.
(b) After graduation, you decided to work overseas to experience living in a country with four seasons. Your neighbour, knowing that you are an engineer asked your help to install a heat pump system for his house. He wanted to always maintain the temperature in his house at 24°C during winter. In that area during winters, average outside temperature is -3°C. He also has an underground water well with average water temperature of 10°C during winter. You estimated that the heat losses from the house under the average outside temperature to be 75000 kJh. Investigate the most economical mean to power the heat pump (by calculating the minimum power required) if you can choose to extract heat from either: i. The outside air at average temperature of -3°c ii. The well water at 10°C State the reasoning for your calculations.
A conference hall is to be i at 24 C dry bulb and 60 %RH. The estimated cooling loads are 75 tons and 25 tons sensible loads and latent loads, respectively. If cooled air from Air Handling Unit (AHU) is supplied to the hall at 15 C, determine the following below & plot the process on the Psychrometric chart. a) room sensible heat factor (RSHF) b) Bypass Factor (BPF) of the cooling coil c) the cubic per minute (CFM) needed to maintain the hall at its comfortable state at 24 C dry bulb and 60 %RH?
b) For an Otto Engine the temperature at the end of combustion is 280 K. If the temperature in the gas side and coolant side of the wall are 177 °C and 127 °C and cylinder wall thickness is 5 mm;
Question 1 A) Considering the First-Law of thermodynamics, describe how we can reduce the temperature of a system? B) There are two different containers; the first one has hot water inside and the second one has cold oil. Can we have an identical thermal energy for these systems? Why?
Consider the PV diagram shown. The diagram shows an ideal gas which starts in state 1 and is taken to state 2 along the depicted path. (The number of moles of the gas is constant in process) A) which statement characterizes the work done during the process and why? 1. Energy enters the gas due to work 2. Energy leaves the gas due to work 3. No energy enters or leaves the gas due to work 4. Not enough information to tell B) is the change in the internal energy of the gas during the process… and why? 1. Positive 2. Negative 3. Zero 4. Not enough information to tell C) which statement characterizes the heat transfer during the process? 1. Energy enters the gas due to heat transfer 2. Energy leaves the gas due to heat transfer 3. No energy enters or leaves the gas to to heat transfer 4. Not enough information to tell
Question 2. A household with electric resistance heating plans to switch from resistive heating to a ground source heat pump. Annual heat consumption of the house is 30 000 kWh. Investment cost of the heat pump is 21 000 €. Heat pumps COP is 4.0. How much are the annual savings compared to resistive heating after the change of the heating system (in kWh)? Average price of electricity is assumed to be 12 c/kWh. Round off your answer to one decimal digit and enter it without the unit.