00:01
So this one, the problem that's written out in the question is not the same as the thing that was copied in.
00:08
So i'm going to do the one that was written out.
00:12
So we have a proton that's moving horizontally with a velocity of 3 .8 times 10 to the 5th meters per second.
00:20
It enters a vertical electric field with a magnitude of 7 .6 times 10 to the 3rd newtons per coulomb.
00:28
And here's the mass of the proton and it's a charge.
00:31
And it's positively charged.
00:33
Okay? so in part a, we want to know, we're given that it's going to travel a distance horizontally of 0 .04 meters.
00:48
That's 4 centimeters.
00:52
Okay? we want to find the time it takes.
00:55
So delta t is delta x over v, which really, that's one of our handy dandy formulas from physics one.
01:07
0 .04 meters divided by 3 .8 times 10 to the 5th meters per second gives us a time of 1 .05 times 10 to the minus 7 seconds.
01:29
Okay.
01:29
So it's going to also move upwards because the electric field, we know that the acceleration in the y direction is going to be qe over m.
01:40
And so the y, y minus y zero, there is no initial velocity in the y direction.
01:53
Comes out to be one half a sub y t squared.
02:00
So that's half...