The Moon's distance from Earth is measured very accurately by bouncing a laser beam off of a small mirror left on the surface of the Moon. If a laser is fired at the Moon and the signal returns in 2.6 seconds, what is the distance to the Moon?
a. 390,000 km
b. 390,000 m
c. 780,000 km
d. 780,000 m
a
RATIONALE: Distance = speed of light × time
You might also like to view...
______________ fossils are those typical of a particular limited time segment of Earth's history
Fill in the blank(s) with correct word
Two children start at one end of a street, the origin, run to the other end, then head back. On the way back Joan is ahead of Mike. Which statement is correct about the distances run and the displacements from the origin?
a. Joan has run a greater distance and her displacement is greater than Mike's. b. Mike has run a greater distance and his displacement is greater than Joan's. c. Joan has run a greater distance, but her displacement is less than Mike's. d. Mike has run a greater distance, but his displacement is less than Joan's. e. Mike has run a shorter distance, and his displacement is less than Joan's.
A homeowner has a new oil furnace which has an efficiency of 60%. For every 100 barrels of oil needed to heat his house, how much (in barrels of oil) goes up the chimney as waste heat?
a. 20 b. 60 c. 40 d. 80 e. 10
Briefly explain the possible threat of near Earth objects
What will be an ideal response?