Why do we measure some distances in astronomy in light-years and some in astronomical units?
What will be an ideal response?
Consider using millimeters to describe the distance between New York and California, 3,920,000,000 millimeters. This distance is correct, but it is far more convenient to state the distance as 3920 kilometers. Distances in astronomy are huge when compared to distances we measure on Earth. It is simpler and more convenient to use larger distance units for discussion and calculations.
You might also like to view...
Modern observations have shown that the geometry of the Universe is ____
a. flat, and the Universe must be infinite b. flat, and the Universe must not be infinite c. open, and the Universe must be infinite d. closed, and the Universe must be infinite e. closed, and the Universe must not be infinite
A "weightless" astronaut in an orbiting space vehicle is
A) shielded from Earth's gravitational effects. B) beyond the pull of gravity. C) without a support force. D) all of the above E) none of the above
When a metal surface is illuminated with light of wavelength 437 nm,
the stopping potential for photoelectrons is 1.67 V. (c = 3.00 × 108 m/s, h = 6.626 × 10-34 J ? s, e = - 1.60 × 10-19 C, 1 eV = 1.60 × 10-19 J, mel = 9.11 × 10-31 kg) (a) What is the work function of the metal, in eV? (b) What is the maximum speed of the ejected electrons?
Which two circuits are exactly equivalent?
a.
A and B
b.
B and C
c.
C and D
d.
D and E
e.
B and E