You will find the following numbers useful. The speed of light is 3x10^{5} km-sec^{-1}.

1 AU is 1.5x10^{8} km.

One year = about 3x10^{7} seconds.

1 light year is about 10^{13} km.

- 10
^{4}x10^{6}= ? - 10
^{4}/10^{2}=? - (10
^{16})^{1/2}= ? - 6x10
^{2}x3.5x10^{3}=? - (64x10
^{8}x36x10^{12})^{1/2}= ? - How long does it take light to travel from the Sun to Jupiter? (Jupiter is roughly 5 AU from the Sun).
- A radar pulse takes 2 hours to travel from Earth out to an asteroid and return. How far away is the asteroid?
- Two galaxies are moving apart at 15,000 km/sec. If they are 6x10
^{8}ly apart, how long ago did they begin moving apart (assume they separate at a constant speed). Note: Be sure not to mix light years and km as units here. Convert one to the other, it doesn't matter which. - In the previous problem, you got an answer in seconds. How many years is it?