I have yet another problem that I need help with. An elctromagnetic wave with a frequency of 7.0 MHz forms a standing wave pattern on a transmission cable. The velocity of the wave in the cable is 0.95 of the speed of light in a vacuum. the length of the cable is such that the third harmonic has three nodes along the length of the cable, one at each end, and one in the middle. how long is the cable? what is teh distance between the nodes of the 7th harmonic on the cable? I believe that the speed of light in a vacuum is equal to to 3.0 x 10^8 m/s therefore, the velocity of the wave would be 2.85 x 10^8 right? But now where do I go from there? I am not sire what my next step should be.