an object placed 20 cm in front of a mirror is found to have an image 15 cm (a) in front of it, (b) behind the mirror. Find the focal length of the mirror and the kind of mirror in each case.
deepakmishra46:
hyyy
mr. tofee
plz mark brilliant
Answers
Answered by
5
u = +20cm(because it's real); v = +15cm(because it's in front of mirror)
1/f = 1/u + 1/v
f = 60/7cm
f is positive so mirror is concave
u = +20cm; v= -15(because it's behind the mirror)
1/f = 1/u + 1/v
f = -60
1/f = 1/u + 1/v
f = 60/7cm
f is positive so mirror is concave
u = +20cm; v= -15(because it's behind the mirror)
1/f = 1/u + 1/v
f = -60
focal length of a concave mirror is negative
what you want to talk?
hyy kofee
hiiiee
Similar questions