2007-06-21 18:24:50 · 5 answers · asked by lareab 1 in Science & Mathematics ➔ Physics
I am puzzeled by this question. A lens is two way (can see from either direction so its focal point is equidistant from either side. A concave mirror only has one becase light is reflected and does not pass thru.
Is that the answer you are looking for?
2007-06-21 18:30:01 · answer #1 · answered by orion_1812@yahoo.com 6 · 0⤊ 0⤋
A convex mirror has only one, a negative one. A convex lens also has only one.
For a positive focal length, either a lens or a mirror has two.
Use the lens maker's formula;
1/f = 1/o + 1/i
where o= distance to the object, i = distance to the image.
f = is the 'focal' Length of the lens or the mirror.
For positive f two or more lengths can be found.
But for a negative, ...
2007-06-21 18:40:38 · answer #2 · answered by James W 2 · 0⤊ 0⤋
A mirror has only one focus because there is only one side to it. A lens allows light to pass through, so it has a focus on either side.
2007-06-21 18:33:34 · answer #3 · answered by TychaBrahe 7 · 0⤊ 0⤋
Any lens has two refracting surfaces, whereas a mirror has only one reflecting surface.
Therefore, lens has two foci and a mirror has one focus.
If a mirror is manufactured so to have it’s both sides as reflecting surfaces, it too will have two foci.
2007-06-21 18:48:46 · answer #4 · answered by Pearlsawme 7 · 0⤊ 0⤋
Butlens
2016-12-24 19:32:39 · answer #5 · answered by Anonymous · 0⤊ 0⤋