00:01
In this problem, we are dealing with a christmas ornament, which is circular.
00:04
And so no matter what part you'll look at, the image will be going out towards you.
00:08
And so you are going to be dealing with a convex mirror.
00:13
And so we're given the diameter of 9 .2 centimeters.
00:19
Well, we know that half of that is the radius, and half of the radius is our focal length.
00:24
So if we divide this by four, we get a focal length of 2 .3 centimeters.
00:28
And since this is convex, our focal length will be negative.
00:33
We're told that the person is standing 25 centimeters away from this ball, and we want to know where is the image.
00:41
And so we're going to use our equation, distance of the object, one over distance of the image is equal to one over focal length.
00:49
So we have one divided by 25 plus one over distance of the image is equal to negative 1 over 2 .3...