Question

. Two astronauts are 1.90 m apart in their spaceship. One speaks to the other. The conversation is transmitted to earth via electromagnetic waves. The time it takes for sound waves to travel at 346 m/s through the air between the astronauts equals the time it takes for the electromagnetic waves to travel to the earth. How far away from the earth is the spaceship

Answer 1

d= 1650 km.

Step-by-step explanation:

• Assuming that sound waves travel along a straight line at a constant speed of 346 m/s, we can find the time needed for the sound to travel the distance of 1.9 m between the astronauts, just applying the definition of average velocity, as follows:

`t = (\Delta x)/(v) =(1.9m)/(346m/s) = 5.5 msec (1)`

• The electromagnetic waves travel in free space at the same speed of light in vacuum ( since light is a electromagnetic wave indeed), i.e., 3*10⁸ m/s.
• Applying the same formula than in (1) we can solve for the distance d, as follows:

`d = v*t = 3e8 m/s*5.5e-3s = 1650 km (2)`