Question

Radio waves travel at the speed of light, approximately 300,000,000 m/s. Part A How much time does it take for a radio message to travel from the Earth to the Moon and back? The average distance from Earth to the Moon is 384,000 km. Express your answer to three significant figures and include the appropriate units. t t =

Answer 1

Answer:

Step-by-step explanation:

First you want to understand that every time a radio wave goes 300,000,000 meters a second passes, literally what meter per second means.    of course it doesn't go that far, it goes 384,000 one way and then the same distance back, which makes 768,000.  Under a third of the distance to make 1 second, so it will be less than one second.  

You also want to understand the formula for speed.  speed = distance / time.  Whch also means, to find time you can change it to be time = distance / speed.  And hey, we have distance and speed.  768,000 / 300,000,000 = .00256, I'll leave the significant figures to you unless you need help with them.  but that's .00256 of a second.  or .00256 s

Answer 2

Answer: 2.56

Step-by-step explanation:

Given: Radio waves travel at the speed of light, approximately 300,000,000 m/s.

i.e. Speed = 300,000,000 m/s

Distance from Earth to the Moon= 384,000 km

Since 1 km = 1000 m

Then , Distance from Earth to the Moon= 384,000,000 m

Distance from Earth to the Moon and back = 2(384,000,000)=768 ,000,000 m

The formula we use here :

$\text{Time}=\dfrac{\text{Distance from Earth to the Moon and  back}}{\text{Speed}}$

i.e.  $\text{Time}=\dfrac{768 000000}{300000000}=2.56$

Hence, it will take 2.56 seconds  for a radio message to travel from the Earth to the Moon and back.