Week 1 Lecture 4
Solutions at the bottom.

1)  In-video quiz at timepoint 02:24.

Imagine a star is located about 10º; above the horizon, directly west of your position on Earth.  In the local coordinate system (described by altitude, zenith angle and azimuth), which of the following options correctly identifies the star's coordinates? 

a) Altitude = 10º;  Zenith angle = 80º;  Azimuth = 90º;  
b) Altitude = 80º;  Zenith angle = 10º;  Azimuth = 270º;
c) Altitude = 10º;  Zenith angle = 80º;  Azimuth = 270º;
d) Altitude = 80º;  Zenith angle = 10º;  Azimuth = 90º;

2)  In-video quiz at timepoint 02:24.

Which of the following options best describes the amount of the visible sky covered by the circumpolar region for an observer looking out from the North (or South) Pole? 

a) None of the sky  
b) All of the sky
c) Half of the sky
d) A third of the sky

3)  In-video quiz at timepoint 06:39.

Right ascension (abbreviated RA; symbol α) is the angular distance measured eastward along the celestial equator from the vernal equinox to the hour circle of the point in question.[1] When combined with declination, these astronomical coordinates specify the direction of a point on the celestial sphere in the equatorial coordinate system."
Wikipedia - Right ascension, http://en.wikipedia.org/wiki/Right_ascension 

Solutions:

1) Correct answer is c) Altitude = 10° Zenith angle = 80° Azimuth = 270°
2) Correct answer is b) All of the sky