A radar signal takes 2.7 s to go to the moon and return. How far away was the moon at the time?

Answer 1

The trick is to remember that we want only the one way time for the radar signal ---

Round trip time is 2.7 seconds. One way trip time is 1.35 seconds.

1.35 seconds times the speed of light (299,792,458 meters per second) = 404,719,818.3 meters to the moon

404,719,818.3 meters = 404719.8183 kilometers to the moon

Answer 2

Since the total "ping time" is 2.7 seconds, the answer can be found by:

Total time of 2.7 seconds divided by 2 = 1.35 seconds for the signal to travel from the Earth to the Moon (and leaving out complications like Doppler and absorption).

This would mean that the signal traveled a distance of 1.35 × 186,171.1164 = a distance of 251,331.0072 miles.

Lunar perigee = 225,609.3 miles
Lunar mean = 238,712.4 miles
Lunar apogee = 251,815.5 miles

Answer 3

Formulla:
Speed = Distance / Time

Speed of Light = 3 x 100000000 m/s (Approx)
Distance = 2 x ( Waves Go and reflect back)
Time = 2.7 Sec

Answer: Distance= 405000000 metres

Answer 4

take the speed of the signal, in distance per second, multiply by the total distance travelled, then divide by 2, assuming the same speed and distance on both the trip and return trip. of course both objects have their own motions, relative to other objects and each other, which would change the distance during the entire trip. once more the distance will have an average distance, whereas time is relative to the observer!

Answer 5

186,000 miles / sec * 2.7 sec / 2 = 251100 miles

or
300,000 km /sec * 2.7 sec / 2 = 4050000 km

The first two guys gave you the distance of the round trip.

Answer 6

186,000 miles * 2.7 = ??

or
300,000 km * 2.7 = ???

pretty easy really

Answer 7

Maybe, yeah

Answer 8

2.7seconds multiplied by 'c' (light speed)

Answer 9

really, really far away

Answer 10

very good question