00:01
So here we know that the mass is equaling 0 .195 grams.
00:04
We can convert to kilograms and say 0 .000195 kilograms.
00:10
We know that the charge is going to be negative 2 .50 times 10 to the negative 8th kulams.
00:18
And then we know that the velocity is 40 ,000 meters per second.
00:24
And again, this is upwards.
00:27
So in order to find, we need to take note that, because the charge is negative, this means that the magnetic force is going to be opposite to the right -hand rule direction.
00:39
So, again, because it's negative, when we're using the right -hand rule to find the direction of the magnetic force, it's going to be opposite of that because, again, the charge is negative.
00:51
So if we were to draw this, we have a negatively charged particle here.
00:55
Going upwards is going to be the velocity.
00:58
The weight is going to be into the page.
01:03
Sorry, the weight is going to be directed out of the page rather, and the magnetic force is going to be directed into the page.
01:17
So we can say that the force of gravity equals the magnetic force, mg equals the absolute value of the charge, times the velocity, times the magnitude of the magnetic field, times sine of phi.
01:32
Sign of phi in this case is going to be simply one...