Why do many planetary nebulae show ring-like features on the sky instead of spheres?
What will be an ideal response?
Asymmetry is the rule in planetary nebulae rather than the exception. A number of causes have been suggested. A disk of gas around a star's equator might form during the slow-wind stage and then deflect the fast wind into oppositely directed flows. Another star or planets orbiting the dying star, rapid rotation, or magnetic fields might cause peculiar shapes.
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Gas in a constant-volume gas thermometer registers a pressure of 75.0 kPa at 0°C. Assuming ideal behavior, what is the pressure of this gas at 200°C?
A) 120 kPa B) 130 kPa C) 140 kPa D) 150 kPa E) 160 kPa
An object that appears to be smaller on the sky will tend to be
A: closer than one that appears larger. B: farther away than one that appears larger. C: there will be no trend.
Arnold Strongman and Suzie Small each pull very hard on opposite ends of a rope in a tug-of-war. The greater force on the rope is exerted by
A) Arnold, of course. B) Suzie, surprisingly. C) both the same, interestingly.
An ice skater performs a pirouette (a fast spin) by pulling in his outstretched arms close to his body. What happens to his rotational kinetic energy about the axis of rotation?
A) It changes, but it is impossible to tell which way. B) It increases. C) It does not change. D) It decreases.