I have two questions that I don\'t really understand how to answer. Explanations
ID: 1470378 • Letter: I
Question
I have two questions that I don't really understand how to answer. Explanations are appreciated. Thanks
1.) A mirror produces an image that is located 32.00 cm behind the mirror when the object is located 16.00 cm in front of the mirror.
(a) What is the focal length of the mirror?
= cm
(b) Is the mirror concave or convex?
2.) A concave mirror (f = 53 cm) produces an image whose distance from the mirror is one-third the object distance.
(a) Determine the object distance.
= cm
(b) Determine the (positive) image distance.
= cm
Explanation / Answer
1)
a) given data
object distance, u = 16 cm
image distance, v = -32 cm (negative sign indicates the image is virtual)
use, 1/f = 1/u + 1/v
1/f = 1/16 + 1/(-32)
f = 32 cm
b) the mirror is concave. Beacuse, f is positive.
2)
a) given, f = 53 cm
let u is object distance and v is image distance.
v = u/3
use, 1/u + 1/v = 1/f
1/u + 1/(u/3) = 1/f
1/u + 3/u = 1/f
4/u = 1/f
==> u = 4*f
= 4*53
= 212 cm
b) v = u/3
= 212/3
= 70.67 cm