# Physical Science/light

posted by
**Angie** on
.

An object 5 millimeters high is located 15 millimeters in front of a plane mirro. How far from the mirror is the image located?

The focal length f of a plane mirror is infinity and 1/f = 0. The optical equation becomes

1/Do + I/Di = 1/f = 0

Do is the distance to the object and Di is the distance to the image (measured on the same side of the mirror).

Therefore Do = -Di The minus sign in front of Di means that the image appears on the other side of the mirror, an equal distance away from it.

wrong answer it has to be 5.0 millimeters or 7.5 millimeters or 15 millimeters or 30 millimeters

which one is it though?

An airplane reaches its takeoff speed of 60m/s in 30s starting from rest. the time it spends in going from 40m/s to 60m/s is

15 m I think, i have the same homework