An object is 39.8 cm away from a thin lens. The image is -60 cm away from the lens. What is the focal length? Is the lens concave or convex? Is the image upright or inverted? Is the image real or virtual?
The focal length of the lens is .....?
Given,
o = 39.8 cm ; i = -60 cm ;
We know from lens eqn
1/f = 1/i + 1/o
1/f = 1/39.8 - 1/60
f = 118.22 cm
lens is convex since f is positive
M = -i/o = -(-60/39.8) = +1.5
Since the magnification is positive, the image is UPRIGHT
since the image distance is negative, its VIRTUAL
An object is 39.8 cm away from a thin lens. The image is -60 cm away...