Question 14
Light and ReflectionThe driving mirror of a car has a radius of curvature of 1 m. A vehicle behind the car is 4 m from the mirror. Find the image distance behind the mirror.
- A.8/7
- B.4/9
- C.9/2
- D.4/7
Show the answer and explanation
Answer: B (4/9)
Explanation
A driving mirror is convex, so f = −r/2 = −0.5 m. 1/v = 1/f − 1/u = −2 − ¼ = −9/4, so v = −4/9 m: a virtual image 4/9 m behind the mirror.