Physics  please, I really need this
posted by Sara .
Show mathematically that a diverging lens will alway produce an upright image. [i.e. prove that hi is positive if f is negative]
I'm not even sure how to start this. Can someone please help me?

You get an upright (virtual) image if the magnification is a negative number. The magnification is the ratio of the image distance si to the object distance so. The lens equation says that
1/so + 1/si = 1/f
If f is negative and so is positive, si must be negative. Therefore si/so must be negative also. 
okay, but I'm not sure how that explains it algebraicall, could you please elaborate?

If 1/f is negative (as it is for a diverging lens), both so and si cannot be positive. That is the best is can do with the algebra.
You are restricted to positive values so (the object distance) with the source in front of the lens.
Respond to this Question
Similar Questions

Physics
A lamp 10 cm high is placed 60cm in front of a diverging lens of focal length 20 cm. By means of a scale ray digram, locate the image and determine the height. I'm not too sure how i would find the distance of the image, as it is a … 
Physics
Show mathematically that a diverging lens will alway produce an upright image. [i.e. prove that hi is positive if f is negative] I'm not even sure how to start this. Can someone please help me? 
Physical Science
Need help please. the once with the ( ) is my answer but i am not sure if it right. Thanks for your help. 15. If the distance from a converging lens to the object is less than the focal length of the lens, the image will be A. real, … 
Physics
An object is placed 30mm in front of a lens. An image of the object is located 90mm behind the lens. a) Is the lens converging or diverging? 
Physics
(a) A 2.20 cm high insect is 1.24 m from a 135 mm focallength lens. What is the image distance? 
physics
A converging lens (f1 = 24.0 cm) is located 56.0 cm to the left of a diverging lens (f2 = 28.0 cm). An object is placed to the left of the converging lens, and the final image produced by the twolens combination lies 20.3 cm to the … 
Physics
i have a question on thin lens equation how do i know when di is positive or negative? 
Physics
An object is placed in front of a converging lens in such a position that the lens (f = 13.2 cm) produces a real image located 23.5 cm from the lens. Then, with the object remaining in place, the lens is replaced with another converging … 
Physics
A lighted candle is placed 38 cm in front of a diverging lens. The light passes through the diverging lens and on to a converging lens of focal length 10 cm that is 5 cm from the diverging lens. The final image is real, inverted, and … 
Physics
A DIVERGING lens has a focal length of 35 cm. (a) Find the image distance when an object is placed 48 cm from the lens. (b) Is the image real or virtual magnified or reduced?