An "onion skin" shell burning structure develops in:
A. a star much less massive than the Sun.
B. a white dwarf.
C. a star like the Sun.
D. a neutron star.
E. a star much more massive than the Sun.
Answer: E. a star much more massive than the Sun.
You might also like to view...
A stainless steel pin fin 5-cm-long, 6-mm-OD, extends from a flat plate into a 175 m/s air stream as shown in the sketch. Estimate (a) the average heat transfer coefficient between air and the fin. (b) the temperature at the end of the fin. (c) the rate of heat flow from the fin with glycerol at 20°C flowing over the fin at 2 m/s. The plate temperature is 50°C.
GIVEN
• A stainless steel pin fin in an air stream
• Pin length (L) = 5 cm = 0.05 m
• Pin diameter (D) = 6 mm = 0.006 m
• Glycerol velocity (U?) = 2 m/s
• Glycerol temperature (T?) = 20°C
• Plate temperature (Tp) = 50°C FIND
(a) The average heat transfer coefficient ( h c) (b) The temperature of the end of the fin (TL) (c) The rate of heat flow from the fin (qf) ASSUMPTIONS
• Steady state
• Turbulence in the glycerol approaching the fin is low
• Radiative heat transfer is negligible
• Steel is type 304
• Steel properties are uniform
• Variation of the thermal properties of glycerol and steel with temperature is negligible
PROPERTIES AND CONSTANTS
Thermal conductivity (k) = 0.285 W/(m K) Kinematic viscosity (?) = 1175 × 10–6 m2/s Prandtl number (Pr) = 12,609 for type 304 stainless steel ks = 14.4 W/(m K) at 20°C
A sphere is constructed of two concentric pieces. The inner part is a solid sphere of radius 10.0 cm made of a material with density 4000 kg/m3
The outer part is a spherical shell with inner radius 10.0 cm and outer radius 20.0 cm. The outer shell has a density 9000 kg/m3. (a) What is the mass of this sphere? (b) What is the average density of this sphere?
The protective shells that many sea organisms grow are not minerals because they
A) are not calcium carbonate. B) are organic. C) are made of ooze. D) become compacted.
At a certain elevation, the ________ , the air becomes saturated and water-vapor molecules ________
A) lifting condensation level; condense to mark the base of cloud formation B) equilibrium level; condense to mark the base of cloud formation C) lifting condensation level; stabilize and mark the upper limit of cloud formation D) equilibrium level; stabilize and mark the upper limit of cloud formation