YANG69GO YANG69GO Science Answered 1-20. What is the frequency of the wave if it is travelling through a vacuum and has a length of 250 000meters? ( Note : v= 3 x 10 8 m/s)21-40. What is the length of the wave that is travelling at a speed of 200 m/s and has a frequency of 5.0 x10⁴ Hz ?