Chapter 7, Problem 4CP

In direct calorimetry, a person is placed in a large, water-insulated chamber. The chamber is kept at a constant temperature. While in the chamber, the subject is asked to perform a number of normal activities, such as eating, sleeping, and exercising. The rate of heat released from the subject’s body can be measured by the rate of heat gain by the water bath. Would direct calorimetry be a practical way to measure metabolic rate? Why or why not?A person is placed inside a calorimetric chamber for 24 hours. During this time, the 660-gallon water bath heats up by 3.2°F. What is the subject’s metabolic rate during this period? Report your answer in kcal/day. Assume that there is no heat loss from the water to the surroundings.

Upon reentry into the Earth’s atmosphere, the bottom of a space shuttle heats up to dangerous levels as the craft slows for landing. If the velocity of the shuttle is 28,500 km/hr at the beginning of reentry and 370 km/hr just prior to landing, how much energy is lost as heat? The shuttle has a mass of 90,000 kg. Assume that the change in potential energy is negligible compared to the change in kinetic energy.

of the basket of the balloon at point A, and their other ends are staked to the ground. The hook is located in the geometric center of the basket. The balloon and the air inside it have a combined mass of 3000 kg. You want to determine the resultant of the tension forces in the four cables acting on the hook at point A. It is known that the magnitudes of the tension in the cables are as follows: TAB = 207 N; TAC = 355 N; TAD = 250 N; and TAE = 486 N. B E 2.5 m C E 5.5 m D 2.5 m 3.5 m 1.5 m Using the information provided in the problem, express the force on the hook at point A by cable AC in rectangular component form. The force on the hook at point A by cable AC in rectangular component form is given below. T AC N) i+ N) + N) R