Suppose we observe a Cepheid variable in a distant galaxy. The Cepheid brightens and dims with a regular period of about 10 days. What can we learn from this observation?
A) It will allow us to calculate the rotation rate of the galaxy.
B) It will allow us to determine the mass of the galaxy.
C) We can learn the distance to the galaxy.
D) Under the rules of the International Astronomical Union, we will be entitled to naming rights for the galaxy.
C
You might also like to view...
A resistor, inductor, and capacitor are connected in series, each with an effective (rms) voltage of 63 V, 176 V, and 65 V, respectively. What is the magnitude of the phase angle in this circuit?
a. 30° b. 64° c. 59° d. 60° e. 69°
The Milky Way:
A) contains less than 50 billion stars. B) stretches across for just around 30,000 light-years. C) is known for being very unique. D) is larger than most other galaxies.
Give at least one example of each of the following:
(a) longitudinal standing wave. (b) transverse standing wave.
A 1-kg ball is released from a height of 6 m, and a 2-kg ball is released from a height of 3 m. Air resistance is negligible as they fall
Which of the following statements about these balls are correct? (There could be more than one correct choice) A) As they reach the ground, the 1-kg ball will have more kinetic energy than the 2-kg ball because it was dropped from a greater height. B) As they reach the ground, the 1-kg ball will be moving faster than the 2-kg ball. C) Both balls will reach the ground with the same speed. D) Both balls will reach the ground with the same kinetic energy. E) Both balls will take the same time to reach the ground.