00:02
Okay, so in this problem, we are asked for the speed of a particle that has 1 .5 kiloelectron volts of energy, kinetic energy, and specifically we're out of these values for an electron and a proton.
00:17
So electrons and protons have the same magnitude of charge.
00:22
What really separates them apart is their huge difference in mass, and that's really what's going to make the difference in these speeds.
00:29
So all we really need, aside from the mass, of the mass, of an electron and proton is expression for kinetic energy of any object, any macroscopic object, which is simply 1 1 half mv squared, solving for v, v is equal to root 2k over m.
00:52
Now when we actually do this calculation, we must convert electron volts into joules for this to give us an answer in meters per second.
01:02
So it's worth noting that there are 1 .6 times 10 the negative 19 joules per ev.
01:14
So when we plug in k, 1 .5, k electron volts, we need to multiply by this factor to convert back into joules...