10.1 First Law of Thermodynamics

10.1 First Law of Thermodynamics

• The study of the relationship between heat, work, and the associated flow of energy is called thermodynamics.
• Scientists formulated two fundamental laws after decades of experience with heat phenomena.
• One form of energy can be converted into another, but energy can't be created or destroyed, according to the First Law of thermodynamics.
• The second law, more complex than the first, can be stated in a number of ways which, although they appear different, can be shown to be equivalent.

• The German physician Robert Mayer was one of the first to state the law of energy saving.
• He was reading a book by a French scientist who suggested that the heat produced by animals is due to the slow burning of food in their bodies.
• Lavoisier said that less food is burned by the body in a hot environment than in a cold one.

• The theory of relativity shows that the law ofConservation must include matter which is convertible to energy.

• Many of the crew became sick when the ship reached the tropics.
• He bled his patients.
• The blood from the veins was almost as red as the blood from the arteries.
• This was a verification of Lavoisier's suggestion.

• The brighter color of the venal blood is due to the high oxygen content.
• The lost body heat and work done by the body balance the energy released by the food.

• It is interesting that a fundamental physical law was first suggested from the observation of human physiology, but more evidence had to be presented before it was accepted as a law.

• The calculation of energy balance in living systems is dependent on the preservation of energy.
• The activities of an animal include simply eating, working, and rejecting excess heat by means of various cooling mechanisms.
• The first law allows us to look at the energetics of the animal.
• The numerical calculations presented in Chapter 11 are based on the First Law of Thermodynamics.