An alpha particle is accelerated to a velocity v in a particle accelerator by a potential difference of 1200 V. Which of the following potential differences would be needed to give the alpha particle twice the velocity? A. 7200 V B. 4800 V C. 4100 V D. 2400 V E. 1700 V At first, I thought of a ratio. That means doubling the speed would double the voltage. But, the answer that I thought of, 2400 V, seems too obvious... Is there any certain equation I can use to be certain of my answer? All help is appreciated.