The expression “order of magnitude” corresponds to

a) one factor of ten. b) one factor of two.c) a factor of 2.5d) two factors of ten.

The expression “order of magnitude” corresponds to

a) one factor of ten. b) one factor of two.c) a factor of 2.5d) two factors of ten.

 At the start of the 21st century, the number of

human beings alive on Earth was approximately 6,000,000,000 or

a) 6 to the 9th powerb) 6 to the 9th power of tenc) 6 times ten to the 9th powerd) 6,000 millione) both c and d.

 At the start of the 21st century, the number of

human beings alive on Earth was approximately 6,000,000,000 or

a) 6 to the 9th powerb) 6 to the 9th power of tenc) 6 times ten to the 9th powerd) 6,000 millione) both c and d.

Estimate the answer to 3.04 x 5.3:a) 1.6 b) 16c) 160 d) 1,600e) don’t know

Estimate the answer to 3.04 x 5.3:a) 1.6 b) 16c) 160 d) 1,600e) don’t know

Using the magnitude system of astronomy, how would the brightness of an 8th magnitude star compare to a 7th magnitude star?

a. 10 times brighter than the 7th magnitude star.

b. 10 times dimmer than the 7th magnitude star.

c. 2.5 times brighter than the 7th magnitude star.

d. 2.5 times dimmer than the 7th magnitude star.

Using the magnitude system of astronomy, how would the brightness of an 8th magnitude star compare to a 7th magnitude star?

a. 10 times brighter than the 7th magnitude star.

b. 10 times dimmer than the 7th magnitude star.

c. 2.5 times brighter than the 7th magnitude star.

d. 2.5 times dimmer than the 7th magnitude star.

Four stars magnitudes are 10, 7, -1, -10. Which star appears brightest from the Earth?

a. the first.b. the fourth c. the secondd. the third

Four stars magnitudes are 10, 7, -1, -10. Which star appears brightest from the Earth?

a. the first.b. the fourth c. the secondd. the third

Star X is known to be 10 parsecs away from us and star Y is 50 parsecs away. Which star has the greater parallax angle?

a. Star X b. Star Yc. Neither – their parallax angles are the

same.

Star X is known to be 10 parsecs away from us and star Y is 50 parsecs away. Which star has the greater parallax angle?

a. Star X b. Star Yc. Neither – their parallax angles are the

same.

Which of the following stars is closest to us?a. Procyon (parallax = 0.29 arcsecond)b. Ross 780 (parallax = 0.21 arcsecond)c. Regulus (parallax = 0.04 arcsecond)d. Sirius (parallax = 0.38 arcsecond)

Which of the following stars is closest to us?a. Procyon (parallax = 0.29 arcsecond)b. Ross 780 (parallax = 0.21 arcsecond)c. Regulus (parallax = 0.04 arcsecond)d. Sirius (parallax = 0.38 arcsecond)