Posted by chrystabelle on .
An object 5cm is placed 30cm in front of a concave mirror.The image is 60cm in front of the mirror.Find (a) the focal length of the mirror.(b) the magnification.(c)the size of the image
There is a formula you should have seen by now, for both mirros and lebneses.
1/Do + 1/Di = 1/f
Do is the object distance and Di is the image distance from the mirror., in this case.
1/30 + 1/60 = 1/f
Solve for the focal length f.
For the size of the image, use the fact that the magnification is
Di/Do = 2
That makes the image size 10 cm