ou read in a popular diet blog that the author claims you can lose up to half a pound of body fat per week if, instead of drinking 1.9 liters (i.e., 1.9 kilograms) of water every day, you can eat the same amount of water in the form of ice. The reasoning is that your body must first melt the ice and then bring the ice water up to the body temperature of 37°C, which is a process that requires a significant amount of energy at the expense of “burned” body fat. Thankfully, you just finished discussing heat and phase changes in your physics class, so you can calculate exactly how much energy is expended. The specific heat and latent heat of fusion for water are 4.186 × 103 J/(kg⋅°C) and 3.34×105 J/kg, respectively a) How many kilocalories do you expend when you eat 1.9 kg of ice at 0°C? Note that 1 kcal = 4186 J. b) Assuming the metabolism of one pound of body fat produces 3500 kcal of energy, how many pounds of body fat could you lose in a week just by eating 1.9 kilograms of ice every day?
Latent heat and phase change
A physical process in which a conversion among the basic states or phases of matter, i.e., solid, liquid, and gas takes place under the effect of a certain temperature and pressure is referred to as a phase change. Generally, the phase change of a substance occurs when heat transfer takes place between the substance and its surroundings. Based on the direction in which heat transfer takes place, different types of phase changes can occur.
Triple Point of Water
The branch of physics in which observer deals with temperature related properties is called thermodynamics.
Boiling Point of Water
Everyday examples of boiling is, boiling milk, heating water. One would have observed that when we heat water it goes through various stages and at one point bubbles show in water, and water keeps splashing with bubbles bursting, we in layman terms say that water is boiling.
Freezing Point of Water
In general, the freezing point of water is 0° Celsius, or 32° Fahrenheit. This is the temperature at which water will ordinarily change from its liquid state to its solid state (ice). However, there are certain conditions that can affect the freezing point of water. For example, a liquid may be supercooled or contain impurities so that it does not freeze at the ordinary freezing point.
You read in a popular diet blog that the author claims you can lose up to half a pound of body fat per week if, instead of drinking 1.9 liters (i.e., 1.9 kilograms) of water every day, you can eat the same amount of water in the form of ice. The reasoning is that your body must first melt the ice and then bring the ice water up to the body temperature of 37°C, which is a process that requires a significant amount of energy at the expense of “burned” body fat. Thankfully, you just finished discussing heat and phase changes in your physics class, so you can calculate exactly how much energy is expended. The specific heat and latent heat of fusion for water are 4.186 × 103 J/(kg⋅°C) and 3.34×105 J/kg, respectively
a) How many kilocalories do you expend when you eat 1.9 kg of ice at 0°C? Note that 1 kcal = 4186 J.
b) Assuming the
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