How long does it take for a signal to go from the east coast to the west coast and back to the east coast from a cable modem?
the width of the united states is 2,680 miles and the speed of light is 186 000 miles / sec so 2680/186000 is 0.0144. Assuming there was a direct cable (which there is not) from one end of the US to the other a one way trip could only happen in 14 ms.