If you do not have to use relative physics but classic physics, this is how you solve it:
Speed of light = c = 3 * 10^5 km/s
Speed of your foe respect to you: 0.259c
Speed of the torpedo respect to you: 0.349c
Speed of the torpedo respect your foe: 0.349c - 0.259c = 0.09c
Conversion to km/s = 0.09 * 3.0 * 10^5 km/s = 27000 km/s
Note that this solution, using classic physics do not take into account time and space dilation.
Answer: 27000 km/s
C. Is the da answer to your question!
Answer:
The frequency increases by a factor of 3.
Explanation:
The relation between speed, wavelength and frequency of a wave is given by :

or

A wave travels at a constant speed. If the wavelength is reduced by a factor of 3, it would mean that the frequency increases by a factor of 3 because there is an inverse relationship between wavelength and frequency.
-- There are 80 protons in the nucleus of every atom of Mercury,
but only 8 of them in the nucleus of an atom of Oxygen.
-- Mercury must be warmer than 357°C in order to boil, but Oxygen
must only be warmer than -183°C.
-- Mercury must be colder than -39°C in order to freeze, but Oxygen
must be colder than -219°C.
-- Oxygen is required for human life. Mercury is a deadly poison.