1. Newton's Law of Cooling. A cup of hot coffee has a temperature of 200°F when freshly poured, and is left in a room at 70°F. One minute later the coffee has cooled to 190°F. (a) Assume that Newton's law of cooling applies. Write down an initial value problem that models the temperature of the coffee. (b) Determine when the coffee reaches a temperature of 170°F.

1. Newton's Law of Cooling. A cup of hot coffee has a temperature of 200°F when freshly poured, and is left in a room at 70°F. One minute later the coffee has cooled to 190°F. (a) Assume that Newton's law of cooling applies. Write down an initial value problem that models the temperature of the coffee. (b) Determine when the coffee reaches a temperature of 170°F.

College Physics

1st Edition

ISBN:9781938168000

Author:Paul Peter Urone, Roger Hinrichs

Publisher:Paul Peter Urone, Roger Hinrichs

Chapter13: Temperature, Kinetic Theory, And The Gas Laws

Section: Chapter Questions

Problem 6PE: One of the honest temperatures ever recorded on the surface at Earth was 134F in Death Valley, CA....

See similar textbooks

Similar questions

On a nice winter day at the South Pole, the temperature rises to 60°F. What is the approximate temperature in degrees Celsius?
In cold weather, you can sometimes "see" your breath. What you are seeing is a mist of small water droplets, the same as in clouds and fog. Suppose air leaves your mouth with temperature 35°C and humidity 0.035 kg/m3 and mixes with an equal amount of air at 5°C. and humidity 0.005 kg/m3 What is the relative humidity of the mixed air if its temperature and humidity equal the averages of those of the two original air masses? Represent what happens by plotting three points in a graph like Figure 5.34.
- (a) Compute the amount of heat needed to raise the temperature of 1 kg of water from its freezing point to its normal boiling point. (b) How does your answer to (a) compare to the amount of heat needed to convert 1 kg of water at 100° C to steam at 100°C?
One of the honest temperatures ever recorded on the surface at Earth was 134F in Death Valley, CA. What is this temperature in Celsius degrees? What is this temperature in Kelvin?
3.Newton’s law of cooling states that the temperature of an object changes at a rate proportional to the difference between its temperature and that of its surroundings. Suppose that the temperature of a cup of coffee obeys Newton’s law of cooling. If the coffee has a temperature of 200◦F when freshly poured, and 1 min later has cooled to 190◦Fin a room at Tm◦F, determine when the coffee reaches a temperature of 150◦F. Use Tm= 80
34 - In a place where the pressure is 102 kPa and the temperature is 33ºC, the mouth of an empty 27-liter bottle is opened and filled with air. What is the mass of the air filled into the bottle? a) 0.0314 kg B) 0.0229 kg NS) 0.0019 kg D) 0.0026 kg TO) 0.0407 kg
1.What is the heat in Joules required to raise the temperature of 25 grams of water from 0 °C to 100 °C? What is the heat in calories? 2.An unknown metal weighing 900g at an initial temperature 140oC is placed into an insulated container holding 3L of water at an initial temperature of 60oC. The water rose to 65oC. What is the specific heat capacity of the metal?
Question: 1). Compare the heat needed in taking 1 kg of gold from 25° C to 2700° C to taking 1 kg water from (– 30° C) to 1000° C. Which is more and why? -Given temperature changes don’t happen until the phase changes, there should be some dependance on the amount of stuff (mass) changing phase and there is: Q = m Lv (vaporizing/condensing) Q = m Lf (melting/freezing) -The photos should be helpful
Give an example of how to convert from degrees Fahrenheit to Celsius from miles to kilometers. Explain why a knowledge of metrics is needed in both laboratory and real-world settings.
1. How much heat is conducted in one hour through an iron plate 2.0 cm thick and 100 cm2 in area, the temperature of the two sides being kept at 0 and 20°C? 2. A nickel plate 0.8 cm thick has a temperature difference of 64°C between its faces. It transmits 200kcal/hr through an area of 10cm2. Calculate the thermal conductivity of nickel in cgs units. 3. A container used to store ice is made of wood 5.0 cm thick and has an effective area of 12,000 cm2 and thermal conductivity of 0.00027 cal/cm2-sec-°C/cm. How much ice inside the box would be melted each 24-hour day if the outside temperature is 25°C and the temperature inside the box is 5°C.
Q2. Calculate the rate of heat conduction out of the human body, assuming that the core internal temperature is 37.0C , the skin temperature is 34.0C , the thickness of the tissues is about 2cm, and the surface area is 2 m^2. How much heat is lost in one hour?[thermal conductivity of human skin = 0.2 J/(s m C) ]
1. How much energy is lost by 20 kg copper if it is cooled from 50 ℃ to 30℃? 2. A 20 kg metal rod is heated 100oC with 2000 J of energy. What is the specific heat of the metal?