Penny wishes to take a picture of her image in a plane mirror. if the camera is 1.4 m in front of the mirror, at what distance should the camera lense be focused?
Does this have anything to do with 1/di + 1/do = 1/df ?
2006-12-16 02:23:09 · 3 answers · asked by HT2791 1 in Science & Mathematics ➔ Physics
i mean, 1/di + 1/do = 1/f ?
2006-12-16 02:24:00 · update #1
The camera should be focused at twice her distance from the mirror i.e. 2.8m.
This is because the image in a mirror, appears the same distance behind the mirror, as the reflected object is in front of the mirror.
2006-12-16 02:30:17 · answer #1 · answered by Ian Philip 2 · 2⤊ 0⤋
The formula to use is 1/u = 1/f + 1/v. u = obect distance (distance from penny to the camera. v = image distance (distance from camera to image i.e. 1.4m). f = focal point. 1/f is unique for each lens so as you are only using one lens this is constant i.e. the power of the lens. Add the power to 1/1.4 and theres your answer :)
2006-12-16 02:52:22 · answer #2 · answered by Anonymous · 0⤊ 1⤋
She just needs to focus for the distance she is from the mirror. No need to double anything.
2006-12-16 03:06:48 · answer #3 · answered by bestonnet_00 7 · 0⤊ 0⤋