A star of apparent magnitude 6 appears ________ times brighter than a star of apparent magnitude 7.
A. 1.00
B. 0.5
C. 13.0
D. 2.51
E. 10.0
Answer: D
You might also like to view...
The microwave emission detected by Arno Penzias and Robert Wilson fits a blackbody spectrum with a temperature of about ____
a. 0 K b. 273 K c. 27 K d. 7.2 K e. 2.7 K
The four seasons—spring, summer, fall, and winter—are caused by the Sun's changing its daily altitude over a period of 1 year. The Sun's altitude changes
a. simply because Earth revolves eastward about the Sun. b. simply because Earth rotates on its axis. c. simply because Earth's axis is tilted 23.5° from the normal to the ecliptic plane. d. because of the combined effects of (A) and (C).
Tritium has a half-life of 12.3 years. How many years will elapse when the radioactivity of a tritium sample diminishes to 30% of its original value?
a. 29 years c. 86 years b. 21 years d. 57 years
A dam is thicker at the bottom than at the top because
A) water is denser at deeper levels. B) water pressure is greater at deeper levels. C) water is cooler at deeper levels. D) dams look better. E) none of the above