Author Question: If the communication lifetime of civilizations in our galaxy is 10,000 years and our galaxy is 13 ... (Read 48 times)

Yolanda · **on:** Jul 27, 2018

If the communication lifetime of civilizations in our galaxy is 10,000 years and our galaxy is 13 billion years old, what is the chance of us detecting another intelligent civilization now?

A) 1 in 13,000
B) 1 in 1,300,000
C) 1 in 1300
D) 1 in 130,000

Question 2

Water runs out of a horizontal drainpipe at the rate of 120. liters per minute. It falls 3.20 m to the ground. Assuming the water doesn't splash up, what average force does it exert on the ground?

A) 12.0 N
B) 19.6 N
C) 15.8 N
D) 8.88 N
E) 6.20 N