When astronomers use Hubble's law to measure the distance to a galaxy they have to measure the ________ of the galaxy.

A. mass
B. recessional speed
C. rotational speed
D. luminosity


Answer: B

Physics & Space Science

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Photon Energy: If the wavelength of a photon is doubled, what happens to its energy?

A. It is reduced to one-half of its original value. B. It stays the same. C. It is doubled. D. It is increased to four times its original value. E. It is reduced to one-fourth of its original value.

Physics & Space Science

The ram of a pile driver drops onto the top of an iron beam, driving it partway into the ground. The distance that the beam sinks into the ground depends on the

A) initial height of the ram. B) initial potential energy of the ram. C) kinetic energy of the ram when it first hits the beam. D) all of the above

Physics & Space Science

A rocket, initially at rest, is fired vertically with an upward acceleration of 10 m/s2 . At an altitude of 0.50 km, the engine of the rocket cuts off. What is the maximum altitude it achieves?

a. 1.9 km b. 1.3 km c. 1.6 km d. 1.0 km e. 2.1 km

Physics & Space Science

Determine the equivalent capacitance of the combination shown when C = 12 pF



a.
48 pF

b.
12 pF

c.
24 pF

d.
6.0 pF

e.
59 pF

Physics & Space Science