A 0.15 kg baseball flies rightward at 15m/s to hit a tennis ball flying at it from the opposite direction at 22m/s. The baseball and the tennis ball have final speeds of
1.2m/s and 13m/s, respectively, both to the right.
What is the mass of the tennis ball?

To solve this problem you must apply the proccedure shown below:
 1. The formula for calculate the distance in parsecs to a star, which is:
 d=10^[(m-M)+5)/5]
 Where m is the apparent  magnitude and M is the absolute magnitude.
 2. Therefore, you have:
 - Distance of Cutter:
 d=63.09 parsecs
 - Distance of Casper:
  d=6.30 parsecs
 Therefore, the answer is: Casper.