g An astronaut must journey to a distant planet, which is 189 light-years from Earth. What speed will be necessary if the astronaut wishes to age only 12 years during the round trip? (Give your answer accurate to four decimal places.)

The value is

Explanation:

From the question we are told that

   The time taken to travel to the planet from earth is

    The  time to be spent on the ship is  

Generally speed can be obtained using the mathematical relation represented below

The 2 in the equation show that the trip is a round trip i.e going and coming back

=>    

=>    

the duration of a photographic flash is related to an rc time constant, which is 0.100 μs for a certain camera.

the doppler effect is used by weather forecasters to measure 

moving clouds