The range of distances that has remained habitable for the entire duration of the Sun's lifetime is referred to as the
A) continuously habitable zone
B) habitable zone of consistency
C) zone of water stability
D) permanently habitable zone
A
You might also like to view...
What is the phase of the Moon shown in the above image?
a. waxing gibbous b. third quarter c. waning gibbous d. first quarter
Current evidence suggests that many massive jovian planets orbit at very close orbital distances to their stars. How do we think these planets ended up on these close orbits?
A) These planets are jovian in nature and were able to form close to their stars because their solar nebulas were very cold in temperature. B) These planets migrated inward after being born on orbits much farther from their stars. C) Despite their large masses, these planets are terrestrial in nature and therefore could form in their inner solar systems. D) These planets were captured from other solar systems.
An ideal gas is allowed to expand adiabatically. Assume the process is reversible. What is the change in entropy?
a. 0 b. nR ln (V2/V1) c. nR ln (T2/T1) d. kn ln (V2/V1) e. kn ln (T2/T1)
The human body is typically modelled as a vertical cylinder that is 1.8 m high and is 30 cm in diameter, as shown in the figure. Calculate the average rate of heat loss from this body, which is maintained at 37°C, on a windy day when the airstream has a 5 m/s velocity and is at 35°C. To ascertain “wind chill” effects, compare this result with the heat loss that would occur in “stagnant” conditions, or when it is not windy and the heat transfer is only by natural convection (consider an average heat transfer coefficient of 3.6 W/(m2 K) for free convection). What is the wind chill effect if the wind got stronger (10 m/s) and colder (25°C)? Even though the natural convection heat transfer coefficient also changes somewhat (as discussed later in Chapter 8), for this calculation
consider it to remain the same. Moreover, compare the heat loss in both cases with the typical energy intake, or metabolic heat production from consumption of food, of about 1033 kcal/day and comment upon your results.
GIVEN
• Human body modeled as a cylinder in an air stream
• Body surface temperature (Ts) = 37°C
• Air velocity (V?) = 5 m/s
• Air temperature (T?) = 35°C
• Cylinder diameter (D) = 30 cm = 0.3 m
• Cylinder height (H) = 1.8 m
FIND (a) The heat loss from the idealized human body
(b) Heat loss if the wind speed is 10 m/s and its temperature is 250C. (c) Compare with the free convection results of Problem 5.8 and with the typical food
consumption rate of 1033 kcal/day
ASSUMPTIONS
• Air velocity is perpendicular to the axis of the cylinder
• Air flow approaching cylinder is laminar
• Heat transfer from the ends can be neglected
SKETCH
PROPERTIES AND CONSTANTS
Thermal conductivity (k) = 0.0262 W/(m K) Kinematic viscosity (?) = 17.1 × 10–6 m2/s Prandtl number (Pr) = 0.71 At the surface temperature of 37°C Prs = 0.71