What is light pollution?
What will be an ideal response?
Light pollution is the brightening of the night sky by light scattered from artificial outdoor lighting. Light pollution can make it impossible to see faint objects. In fact, many residents of cities are unfamiliar with the beauty of the night sky because they can see only the brightest stars. Radio astronomers face a problem of radio interference analogous to light pollution. Weak radio signals from the cosmos are easily drowned out by human radio interference-everything from automobiles with faulty ignition systems to poorly designed transmitters in communication. To avoid that, radio astronomers locate their telescopes as far from civilization as possible. Hidden deep in mountain valleys, they are able to listen to the sky protected from human-made radio noise.
You might also like to view...
You hold one end of a solid rod in a fire, and the other end becomes hot. This is an example of
a. heat conduction b. heat convection c. heat radiation d. thermal expansion e. none of the above
Jupiter, Saturn, Uranus and Neptune are only located at a distance of 1 AU or less from the Sun
a. True b. False Indicate whether the statement is true or false
Two objects are connected by a very light flexible string as shown in the figure, where M = 0.60 kg and m = 0.40 kg. You can ignore friction and the mass of the pulley
(a) Draw free-body diagrams for each object. (b) Calculate the magnitude of the acceleration of each object. (c) Calculate the tension in the string. What will be an ideal response?
Exhibit 12-1
The figure below shows a graph of angular velocity versus time for a woman bicycling around a circular track.
?
?
Use this exhibit to answer the following question(s).
Refer to . What is her angular displacement (in rad) in the first 12 minutes?
a.
0
b.
2?
c.
4?
d.
16?
e.
32?