The major observational difference between a Seyfert galaxy and a normal spiral galaxy is that, unlike a normal spiral galaxy, a Seyfert galaxy:
A) usually has shorter spiral arms.
B) does not have a black hole at its center.
C) has a small, highly luminous nucleus in its bulge.
D) does not contain young stars in its spiral arms.
C
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A single-shell-eight-tube-pass heat exchanger is used in a power plant to preheat 55ºF water to 80ºF by using 190ºF hot water and cooling it to 160ºF. If the overall heat exchanger conductance is 400 Btu/hr?ft^2 ?0F and if 1800 lbm/min of 55ºF water is preheated, determine (a) mass flow of the hot water and (b) surface area of the heat exchanger.
What will be an ideal response?
A weight watcher who normally weighs 400 N stands on top of a very tall ladder so she is one Earth radius above Earth's surface. How much is her weight there?
A) 0 B) 100 N C) 200 N D) 400 N E) none of the above
Planet Z-34 has a mass equal to one-third that of Earth and a radius equal to one-third that of Earth. With g representing, as usual, the acceleration due to gravity at the surface of Earth, the acceleration due to gravity at the surface of Z-34 is
A) g/3. B) 3g. C) 6g. D) g/9. E) 9g.
In sublimation the saturation region involves solid and vapor phases. Where would you expect convection to be dominant, in the saturated solid or the saturated vapor?
What will be an ideal response?