A pound of body fat stores an amount of chemical energy equivalent to 3,500 Cal. When sleeping, the average adult burns or expends about 0.44 Cal/h for every pound of body weight. How long would the person have to sleep continuously to lose 1 lb of body fat? (Assume the person weighs 145 lb.)

You mix mI = 1.2 kg of ice at TI = -19°C with mW = 3.4 kg of water at TW = 86°C in an insulated container. The specific heats of ice and water are cI = 2.10×103 J/(kg⋅°C) and cW = 4.19×103 J/(kg⋅°C), respectively, and the latent heat of fusion for water is Lf = 3.34 × 105 J/kg. Enter an expression for the final equilibrium temperature of the mixture in terms of the defined quantities.  Hints : Heat problems involving phase changes generally need to be dealt with step by step, taking into account that when there is no temperature difference, there will be no heat transfer. In the present case, the first step might be to consider whether the ice warms to 0°C before or after the water cools to 0°C.-In an isolated system all the heat lost by any components of the system is gained by the system’s other components.-Use the relation among heat, mass, specific heat, and temperature change.-First, the ice reaches 0°C. Then it starts melting while the warmer water continues cooling. Now consider…

Consider a block of ice, with a mass of 2.00 kg and an initial temperature of -8.00°C.

Hello, Can you please answer this question?   The heat of combustion of gasoline is approximately 47 kJ /g . If a gasoline engine operated between 1500 K and 750 K, what is the maximum height that 5.0g of gasoline can lift an aircraft that weighs 400 kg?

When energy shortages occur, magazine articles sometimes urge us to keep our homes at a constant temperature day and night to conserve fuel. They argue that when we turn down the heat at night, the walls, ceilings, and other areas cool off and must be reheated in the morning. So if we keep the temperature constant, these parts of the house will not cool off and will not have to be reheated. Does this argument make sense? Would we really save energy by following this advice?

The specific heats of aluminum and iron are 0.214 and 0.107 calories per gram degrees Celsius​ [cal/(g °C​)] respectively. If we add the same amount of energy to a cube of each material​ (of the same​ mass) and find that the temperature of the aluminum increases by 27 degrees Fahrenheit ​[°F​], how much will the iron temperature increase in degrees Fahrenheit ​[°F​]?

The giant hornet Vespa mandarinia japonica preys on Japanese bees. However, if one of the hornets attempts to invade a beehive, several hundred of the bees quickly form a compact ball around the hornet to stop it. They don’t sting, bite, crush, or suffocate it. Rather they overheat it by quickly raising their body temperatures from the normal 35 C to 47 C or 48 C, which is lethal to the hornet but not to the bees . Assume the following: 500 bees form a ball of radius R=2.0 cm for a time t= 20 min, the primary loss of energy by the ball is by thermal radiation, the ball’s surface has emissivity ´=0.80, and the ball has a uniform temperature. On average, how much additional energy must each bee produce during the 20 min to maintain 47 C?

One liter of gasoline at pump costs $1.2. One US gallon of E85 (85% ethanol + 15% gasoline by volume) at pump costs $3.3 (both in Canadian dollars). Traveling from location A to location B via a compact car consumes about 448 MJ of fuel. Which fuel (gasoline or E85) will cost less for this trip?

On a trip, you notice that a 6.82 kg bag of ice lasts an average of 1 day in your cooler. What is the average power absorbed by the ice if the ice starts at 0°C and completely melts to liquid water at 0°C in exactly 1 day? The latent heat of fusion for water is 334 kJ/kg. Give your answer in units of watts. Question Credit: OpenStax College Physics P =

Aluminum is often melted down for recycling purposes. Assuming 1 kg of aluminum is at 20 deg C (room temperature), what is the minimum amount of heat needed to melt it to a liquid? The specific heat capacity of aluminum is 899 J/kg°C, the melting point is 660°C, and the latent heat of fusion is 3.97 x 105 J/kg. 972,000 J571,000 J397,000 J500,000 J