Ok, so I have this problem and I can't figure out where to go because I'm missing the mass. This is the problem: There is a test charge of +1.0 C. 10 meters away, a negative charge of -0.2 is released. Find the speed of the negative charge when it is 2 meters away from the positive charge. Is there a way I can get the mass of these charges if I wasn't given them in the first place? Sorry, I'm really rusty with Physics.