00:01
So we're going to have a side view mirror of an automobile, and those mirrors are actually convex.
00:09
Right.
00:09
So again, if you had an image here, the light would spread out.
00:15
And it tells us that the radius of curvature is 11 .3 centimeters.
00:21
Now, what we know is that the focal length is half of that.
00:26
And because it's a convex mirror, it's actually negative.
00:30
The other thing we know is that the magnification, which is negative q over p, is positive one -third.
00:40
And it says it's one -third because it's one -third the size of the object, but it's a virtual image, right? and that virtualness tells us that it's positive as well, because it's going to be an upright image.
00:54
So from this, negative q over p equals one -third, we can actually solve for p.
01:00
In terms of q.
01:02
And when you, or q in terms of p, it doesn't matter.
01:06
Or q is negative p over 3...