Sometime within the next million years or so, their planet is likely to be doomed because
A) jets of material shot out of the accretion disk will shoot down their planet.
B) their planet receives most of its energy from the red giant. However, this star will soon be completely devoured in the accretion disk and thus will no longer exist.
C) the red giant will probably undergo a supernova explosion within the next million years.
D) tidal forces from the black hole will rip the planet apart.
E) the planet's orbit gradually will decay as it is sucked in by the black hole.
C
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In a(n) _____________reaction, two solid phases ? and ? react to form one solid phase ?.
Fill in the blank(s) with the appropriate word(s).
Conducted in 1953, the ________ experiments were designed to show what types of complex molecules might have formed in the Earth's primitive environment
Fill in the blank(s) with correct word
There is a 10-A current through a wire for 2.0 min. (e = 1.60 × 10-19 C)
(a) How much charge has passed through this wire? (b) How many electrons have passed any point in the wire?
Solar One, located near Barstow, CA, was the first large-scale (10 MW electric) solar- thermal electric-power-generating plant in the United States. A schematic diagram of the plant is shown below. The receiver may be treated as a cylinder 7 m in diameter and 13.5-m-tall. At the design operating conditions, the average outer surface temperature of the receiver is about 675°C and ambient air temperature is about 40°C. Estimate the rate of heat loss, in MW, from the receiver—via natural convection only—for the temperatures given. What are other mechanisms by which heat may be lost from the receiver?
GIVEN
• A vertical cylinder in air
• Height of cylinder (L) = 13.5 m
• Diameter (D) = 7 m
• Surface temperature (Ts) = 675°C
• Ambient air temperature (T?) = 40°C
FIND
(a) The rate of convective heat loss (qc) in MW
(b) What other mechanisms for heat loss exist?
ASSUMPTIONS
• Air is still
• Surface temperature is uniform and constant
PROPERTIES AND CONSTANTS
for dry air at the mean temperature of 357.5°C
Thermal expansion coefficient (?) = 0.00160 1/K
Thermal conductivity (k) = 0.0461 W/(m K)
Kinematic viscosity (?) = 58.1 × 10–6 m2/s
Prandtl number (Pr) = 0.72