Why are Cepheid variable stars important in our study of the Milky Way galaxy?
What will be an ideal response?
They can be used to calibrate the period-luminosity relation, which is used to determine distances to stars.
You might also like to view...
A box is being pulled across a rough floor at a constant speed. What can you say about the work done by friction?
a) friction does no work at all b) friction does negative work c) friction does positive work
We do not know for certain whether the general trends we observe in stellar birth masses also apply to brown dwarfs. But if they do, then which of the following would be true?
A) Brown dwarfs would be responsible for most of the overall luminosity of our Milky Way Galaxy. B) Most of the brown dwarfs in the Milky Way Galaxy would be quite young in age. C) Brown dwarfs would outnumber all ordinary stars. D) Brown dwarfs would be extremely rare.
Rupel pushes a box 7.00 m by applying a 25.0-N horizontal force. What work does she do?
a. 3.57 J b. 0.280 J c. 175 J d. –175.0 J e. 25.0 J
A small metal sphere is suspended from the conducting cover of a conducting metal ice bucket by a non-conducting thread. The sphere is given a negative charge before the cover is placed on the bucket. The bucket is tilted by means of a non-conducting material so that the charged sphere touches the inside of the bucket. Which statement is correct?
a. The negative charge remains on the metal sphere. b. The negative charge spreads over the outside surface of the bucket and cover. c. The negative charge spreads over the inside surface of the bucket and cover. d. The negative charge spreads equally over the inside and outside surfaces of the bucket and cover. e. The negative charge spreads equally over the sphere and the inside and outside surfaces of the bucket and cover.