00:01
Okay, so the question was asking us, what are the direction and magnitude of the electric force exerted by the large sphere on a small sphere? well, we know the magnitude of the electric force would be just simply equal to k -q -q over d -square.
00:19
Since we're talking about, so we put the absolute value here.
00:23
Okay, because we don't know what kind of charge does q have? is it negative or is it positive? we're not sure.
00:31
But let's talk about this.
00:33
So if q is positive, okay? so if q is positive, that means that we also know that lowercase q is positive as well.
00:57
And therefore, it should be a repulsive force between it.
01:01
Okay? then we become repulsive.
01:12
And the direction of the natural force should be toward the small sphere, okay? so toward the small sphere.
01:37
And since this is a repulsive force on a small sphere, that means the small sphere will move away from a large sphere, okay? let's say move away from it.
02:06
And if q, the capital q is negative, and we know that the lower case q is positive, then we know so the electric force from a large sphere will be an attractive force because it's negative...