2. In an electrically heated home, the temperature of the ground in con-tact with a concrete basement wall is 12.8 °C. The temperature at theinside surface of the wall is 20.0 °C. The wall is 0.10 m thick and has anarea of 9.0 m². Assume that one kilowatt · hour of electrical energy costs$0.10. How many hours are required for one dollar's worth of energy tobe conducted through the wall?

The rate of heat conducted through the wall is given as, Here, k, A, l and ΔT represent the thermal…

Answered: 2. In an electrically heated home, the…

University Physics Volume 2

18th Edition

ISBN:9781938168161

Author:OpenStax

Publisher:OpenStax

Chapter1: Temperature And Heat

Section: Chapter Questions

Problem 95P: (a) What is the rate of heat conduction through the 3.00-cm-thick fur of a large animal having a I...

See similar textbooks

Similar questions

How long does a 52 kW water heater take to raise the temperature of 170Lof water from 20°C to 37°C? The specific heat of water is 4186 J/kg-K. The density of water is 1.00 g/cm,
To help keep her barn warm on cold days, a farmer stores 865 kgof warm water in the barn. How many hours would a 2.00-kilowattelectric heater have to operate to provide the same amount of heatas is given off by the water as it cools from 20.0 °C to 0 °C and thenfreezes at 0 °C?
15. A 2 kW electric heater raises the temperature of 400 g of water from 15 °C to 353.15 K. How long does it take, assuming that there is no heat lost to the surroundings?
@ 2 O: F2 W S 8. An electric immersion heater has a power rating of 1900 W. If the heater is placed in a 1.8 kg of water at 30 °C, how many minutes will it take to bring the water to a boiling temperature? (Assume that there is no heat loss except to the water itself. Cwater=4186 J/kg.°C) min # 3 X 80 F3 E D $ 4 C F4 R TI F or do % 5 V F5 T G > 6 MacBook Air B F6 < H 887 & ◄◄ F7 U N * 8 J DII F8 M ( 9 K F9 O ) C L F10 (4) P F11 31 + 11 F12 18 BEL ?
1. A 60 kg student runs up a 300m long, 8.5° ramp at a constant speed of 2.5 m/s on a 25°C day. The student has a surface area of 1.50 m2, 34°C skin temperature, a skin emissivity of 0.90 and muscles that are 25% efficient. The surface transfer coefficient is 8 watts per square metre-degree. If resistance forces on the student amount to 54 N, then find a) the force required to run up the ramp b) the rate at which the student does work c) the rate at which heat energy is generated by the student (joules per second)d) the rate of heat radiation by the skin e) the rate of convective coolingf) the rate of sweating (kg/s) required to maintain constant body temperature given the rate of exercise, radiative emission, and convective heat losses.
A student is trying to decide what to wear.His bedroom is at 20.0 degrees Celcius.His skin Temperature is 25 degrees Celsius.The area of his exposed skin is 1.50 square mitres.People all over the world have dark skin with emessivity about 0.900.Find the net energy transfer from his body by radiation in 10.0 minutes
A small electric immersion heater is used to heat 100 g of water for a cup of instant coffee. The heater is labeled “200 watts”. Calculate the time required to bring all this water from 23.0 °C to 100 °C, ignoring any heat losses. Assume specific heat of water is 4.187 J/g-°C.
Q12. (a) Name any four types of radiation emitted by the sun? (b) A solar hot water system receives solar energy at the rate of 10.5 MJm2 per day. The efficiency of the solar collector is 0.8 and it has an area of 6.0 m2. The collector contains 0.250 m3 volume of water and the density of water is assumed to be 1000 kgm 3. The specific heat capacity of water C 4200 J/Kg. C. (i) Calculate the mass of water? (ii) Estimate the temperature rise of the water in the tank during the day.
1. How long (in seconds) will it take to heat 40 kg of water from 40°C to 80°C with a 20-kW immersion heater? Assume no energy is lost to the environment and specific heat of water is 4.186 kJ/kgoC. 2. The heat of vaporization of water is 2260 kJ/kg and the heat of fusion of water is 335 kJ/kg. Use the specific heat of water is 4.186 kJ/kg·oC 2a) How much energy (in kJ) will it take to raise the temperature of water (15 kg) from 0°C to 100oC? 2b) How much energy (in kJ) would it take to then completely convert the water to steam? 3. You want to raise the temperature of 22kg of water from 60°C to 95°C. If electricity costs $0.08/kWh, how much would it cost you to use an electric heater for this process? Use the specific heat of water is 4.186 kJ/kgoC and 1 kJ = 0.00028 kWh.
A baking dish is removed from a hot oven and placed on a cooling rack. As the dish cools down to 31.0°C from 189°C, its net radiant power decreases to 13.0 W. What was the net radiant power of the baking dish when it was first removed from the oven? Assume that the temperature in the kitchen remains at 24.0°C as the dish cools.
1. If 60 kJ of heat energy are added to 2 kg of water at 30°C, what will be the final temperature of the water? The specific heat of water is 4186 J/kg·°C. 2. How long (in seconds) will it take to heat 40 kg of water from 40°C to 80°C with a 20-kW immersion heater? Assume no energy is lost to the environment and specific heat of water is 4.186 kJ/kgoC. 3. The heat of vaporization of water is 2260 kJ/kg and the heat of fusion of water is 335 kJ/kg. Use the specific heat of water is 4.186 kJ/kg·oC 3a) How much energy (in kJ) will it take to raise the temperature of water (15 kg) from 0°C to 100oC? 3b) How much energy (in kJ) would it take to then completely convert the water to steam? 4. You want to raise the temperature of 22kg of water from 60°C to 95°C. If electricity costs $0.08/kWh, how much would it cost you to use an electric heater for this process? Use the specific heat of water is 4.186 kJ/kgoC and 1 kJ = 0.00028 kWh.
A 500-W, 230-volt electric kettle contains 1.5 kilograms of water. Determine the thermal efficiency of the kettle if the water will boil after 15 mins.

SEE MORE QUESTIONS

Recommended textbooks for you

University Physics Volume 2

Physics

ISBN:

9781938168161

Author:

OpenStax

Publisher:

OpenStax

University Physics Volume 2

Physics

ISBN:

9781938168161

Author:

OpenStax

Publisher:

OpenStax

SEE MORE TEXTBOOKS