Homework Statement
A concave mirror of focal length 10cm in air is put into a beaker containing a liquid up to 7.5cm. Refractive index of the liquid is 1.2. What is the focal length of the mirror inside the beaker?
The Attempt at a Solution
I tried proportion method:
Depth...
I'm sorry but according to your equation, I don't get the answer which is 1.18cm. By the way, I also don't understand the statement "carbon film on its curve surface" means. Do you mind explaining it?
I got it. I thought the increase of L decrease the r to r/1.1.
Can I ask another question about resistance?
A square carbon film of thickness 5x10^-7m, rho 4x10^-5 ohm m is formed on an insulator rod of diameter 3mm.What is the length of the rod so that the carbon film on its curve surface has...
A wire has uniform cross sectional and resistance R. Then the wire is pulled so that the length increases by 10%. How to find the new resistance? Assumption: The wire thins uniformly.
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