Why is light variability a critical issue with the sizes of active nuclei?
What will be an ideal response?
The source of the light cannot be any larger than the time it takes light to cross it and change in brightness, so if the quasar varies in a matter of months, then its light emitting region cannot be more than a few light months wide.
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Suppose we suspend a negatively charged ball like a pendulum inside a hollow but completely enclosing metal box. Assume that the ball hangs a few inches from the box’s left vertical face. Imagine that we now bring a very strong positively charged object to a point just to the left of the box’s left face, so that it is only a few inches away from the suspended ball (though the box’s left face is between them). The ball will be deflected
A. strongly toward the external object. B. strongly away from the external object. C. weakly toward the external object. D. weakly away from the external object. E. not the least little bit.
Which of the following statements about the rings of the four jovian planets is not true?
A) All rings lie within two to three planetary radii of their planet. B) All the particle orbits are fairly circular and near their planet's equatorial plane. C) All have gaps and ringlets. D) All probably look much the same as they did when the solar system first formed. E) All are made of individual particles of rock or ice that orbit in accord with Kepler's laws: inner ring particles orbiting faster, and outer ring particles orbiting slower.
A uniform magnetic field of 0.50 T is directed along the positive x axis. A proton moving with a speed of 60 km/s enters this field. The helical path followed by the proton shown has a pitch of 5.0 mm. Determine the angle between the magnetic field and the velocity of the proton
a.
39°
b.
51°
c.
44°
d.
34°
e.
71°
In what way does the Heisenberg uncertainty principle limit our ability to measure exactly?