As the 21st century began, which of the following is a discovery made by astronomers?

A) The Universe has a center.
B) The expansion of the Universe is actually accelerating.
C) The Universe has an edge.
D) The expansion of the Universe has come to a halt.


B

Physics & Space Science

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Galileo's observation of the satellites of Jupiter showed that ________.

A. the Moon was not a flawless sphere B. nothing orbited Earth C. there were objects that did not orbit Earth D. planets orbited the Sun E. None of these choices is correct.

Physics & Space Science

In general, which type of planet would you expect to cause the largest Doppler shift in the spectrum of its star?

A) a massive planet that is close to its star B) a massive planet that is far from its star C) a low-mass planet that is close to its star D) a low-mass planet that is far from its star

Physics & Space Science

Exhibit 17-1 The figure below shows a sine wave at one point of a string as a function of time. ? ? Use the exhibit to answer the following question(s). Refer to Exhibit 17-1. Which of the graphs below shows a wave where the amplitude and frequency are each reduced in half?

A.


B.

C.

D.

E.

Physics & Space Science

The vertical displacement of a string is given by y(x,t) = (6.00 mm) cos[(3.25 m-1)x – (7.22 s-1)t]. What is the period of the wave?

A) 7.22 s B) 1.93 s C) 0.870 s D) 0.308 s E) 0.139 s

Physics & Space Science