1. (a) The number of kilocalories in food is determined by calorimetry techniques in which the food is burned and the amount of heat transfer is measured. How many kilocalories per gram are there in a 5.2 -g peanut if the energy from burning it is transferred to 0.5 kg of water held in a 0.12 -kg aluminum cup, causing a 54.3 °C temperature increase? The specific heat of water is 1.00 kcal/kg °C, and the specific heat of aluminum cup is 0.215 kcal/kg °C. Q kcal/g p (b) Compare your answer to labeling information found on a package of peanuts and comment on whether the values are consistent. A label for unsalted dry roasted peanuts says that 30 g contains 175 calories (kcal). Find the (Q/m) from calorimetry techniques of the label on a box of roasted peanuts. Q m cal Q m label

1. (a) The number of kilocalories in food is determined by calorimetry techniques in which the food is burned and the amount of heat transfer is measured. How many kilocalories per gram are there in a 5.2 -g peanut if the energy from burning it is transferred to 0.5 kg of water held in a 0.12 -kg aluminum cup, causing a 54.3 °C temperature increase? The specific heat of water is 1.00 kcal/kg °C, and the specific heat of aluminum cup is 0.215 kcal/kg °C. Q kcal/g p (b) Compare your answer to labeling information found on a package of peanuts and comment on whether the values are consistent. A label for unsalted dry roasted peanuts says that 30 g contains 175 calories (kcal). Find the (Q/m) from calorimetry techniques of the label on a box of roasted peanuts. Q m cal Q m label

University Physics Volume 2

18th Edition

ISBN:9781938168161

Author:OpenStax

Publisher:OpenStax

Chapter1: Temperature And Heat

Section: Chapter Questions

Problem 67P: (a) The number of kilocalories in food is determined by calorimetry techniques in which the food is...

See similar textbooks

Similar questions

Calculate the rate of heat conduction out of the human body, assuming that the core internal temperature is 37.0 , the skin temperature is 34.0 , the thickness of the fatty tissues between the core and the skin averages 1.00 cm, and the surface area is 1.40 m2.
Suppose you stand with one foot on ceramic flooring and one foot on a wool carpet, making contact over an area of 80.0cm2 with each foot. Both the ceramic and the carpet are 2.00 cm thick and are 10.0C on their bottom sides. At what rate must heat transfer occur from each foot to keep the top of the ceramic and carpet at 33.0C ?
During heavy exercise, the body pumps 2.00 L of blood per minute to the surface, where it is cooled by 2.00C. What is the rate of heat transfer from this forced convection alone, assuming blood has the same specific heat as water and its density is 1050kg/m3 ?
For the human body, what is the rate of heat transfer by conduction through the body's tissue with the following conditions: the tissue thickness is 3.00 cm, the difference in temperature is 2.00 , and the skin area is 1.50 m2. How does this compare with the average heat transfer rate to the body resulting from an energy intake of about 2400 kcal per day? (No exercise is included.)
Find the net rate of heat transfer by radiation from a skier standing in the shade, given the following. She is completely clothed in white (head to foot, including a ski mask), the clothes have an emissivity of 0.200 and a surface temperature of 10.0C, the surroundings are at 15.0C, and her surface area is 1.60m2.
What are the main methods of heat transfer front the hot core of Earth to its surface? From Earth's surface to outer space? When our bodies get too warm, they respond by sweating and increasing blood circulation to the surface to transfer thermal energy away from the care. What effect will this have on a person in at 40.0C hot tub? Figure 14.30 shows a cutaway drawing of a thermos battle (also known as a Dewar flask), which is a device designed specifically to slow down all terms at heat transfer. Explain the functions of the various parts, such as the vacuum, the silvering of the walls, the thin-walled long glass neck, the rubber support, the air layer, and the stopper. Figure 14.30 The construction of a thermos bottle is designed to inhibit all methods of heat transfer.
A high-end gas stove usually has at least one burner rated at 14 000 Btu/h. (a) If you place a 0.25-kg aluminum pot containing 2.0 liters of water at 20.C on this burner, how long will it take to bring the water to a boil, assuming all the heat from the burner goes into the pot? (b) Once boiling begins how much time is required to boil all the water out of the pot?
One easy way to reduce heating (and cooling) costs is to add extra insulation in the attic of a house. Suppose the house already had 15 cm of fiberglass insulation in the attic and in all the exterior surfaces. If you added an extra 8.0 cm of fiberglass to the attic, then by what percentage would the heating cost of the house drop? Take the single story house to be of dimensions 10 m by 15 m by 3.0 m. Ignore air infiltration and heat loss through windows and doors.
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 between averages 1.00 cm, and the surface area is 1.40m2.
A firewalker runs across a bed of hot coals without sustaining burns. Calculate the heat transferred by conduction into the sole of one foot of a firewalker given that the bottom of the foot is a 3.00-mm-thick callus with a conductivity at the low end of the range for wood and its density is 300 kg/m3. The area of contact is 25.0 cm2 the temperature of the coals is 700 , and the time in contact is 1.00 s. Ignore the evaporative cooling of sweat.
How much heat transfer (in kilocalories) is required to thaw a 0.450kg package of frozen vegetables originally at if their heat of fusion is the same as that of water?
The specific heat of substance A is greater than that of substance B. Both A and B are at the same initial temperature when equal amounts of energy are added to them. Assuming no melting or vaporization occurs, which of the following can be concluded about the final temperature TA of substance A and the final temperature TB of substance B? (a) TA TB (b) TA TB (c) TA = TB (d) More information is needed.