When you jog, most of the food energy you burn above your basal metabolic rate (BMR) ends up as internal energy that would raise your body temperature if it were not eliminated. The evaporation of perspiration is the primary mechanism for eliminating this energy. Determine the amount of water you lose to evaporation when running for 58 minutes at a rate that uses 400 kcal/h above your BMR. (That amount is often considered to be the "maximum fat-burning" energy output. The latent heat of vaporization of water at room temperature is 2.5  106 J/kg.) A) _________ kg B)The metabolism of 1 gram of fat generates approximately 8.63 kcal of energy and produces approximately 1 gram of water. (The hydrogen atoms in the fat molecule are transferred to oxygen to form water.) What fraction of your need for water will be provided by fat metabolism? ______________ %

You wish to buy a new freezer for your basement. The primary use of the freezer will be to prepare ice for family parties. You have a very large family, with grandparents, parents, sisters, brothers, uncles, aunts, cousins, nephews, nieces, and grandchildren. As a result, family birthday parties are held every couple of weeks, and you need lots of ice for drinks. You want the freezer to convert 10.6 kg of water at 23.0°C to 10.6 kg of ice at −9.2°C in 2.00 h. But, in order to keep your electric bill down, you want the power rating of the freezer to stay below 100 W. From these requirements, you determine the minimum COP of the freezer that will satisfy your needs. (Consider that the specific heat of water is 4,186 J/(kg · °C), the specific heat of ice is 2,090 J/(kg · °C), the latent heat of fusion of water is 3.33 ✕ 105 J/kg, and the latent heat of vaporization of water is 2.26 ✕ 106 J/kg.)

A weather balloon contains 12.0 m³ of hydrogen gas when the balloon is released from a location at which the temperature is 30.0°C and the pressure is 80.0 kPa. The balloon rises to a location where the temperature is -10.0°C and the pressure is 20.0 kPa. If the balloon is free to expand so that the pressure of the gas inside is equal to the ambient pressure, what is the new volume of the balloon? Assume that in both cases the hydrogen gas is in thermal equilibrium with the outside air. O 14.0 m³ 4.16 m³ 16.0 m³ 41.7 m³ 2.38 m³

You wish to buy a new freezer for your basement. The primary use of the freezer will be to prepare ice for family parties. You have a very large family, with grandparents, parents, sisters, brothers, uncles, aunts, cousins, nephews, nieces, and grandchildren. As a result, family birthday parties are held every couple of weeks, and you need lots of ice for drinks. You want the freezer to convert 10.6 kg of water at 21.0°C to 10.6 kg of ice at −8.8°C in 2.00 h. But, in order to keep your electric bill down, you want the power rating of the freezer to stay below 100 W. From these requirements, you determine the minimum COP of the freezer that will satisfy your needs. (Consider that the specific heat of water is 4,186 J/(kg · °C), the specific heat of ice is 2,090 J/(kg · °C), the latent heat of fusion of water is 3.33 ✕ 105 J/kg, and the latent heat of vaporization of water is 2.26 ✕ 106 J/kg.) Find the coefficient of performance (COP).