Question

The device is opened up, revealing a single convex lens. The same person from before tells you that the object is 10.0 cm away from the lens, and that the projected image is 4 times the size as the original object. What is the focal length of the lens?

a. 2.86 cm
b. 6.05 cm
C. 8.00 cm
d. 9.50 cm

Answer 1

The focal length of the lens can be determined using the lens formula. In this case, the focal length is 8.00 cm.

Step-by-step explanation:

The focal length of the lens can be determined using the lens formula, which states that 1/f = 1/v - 1/u, where f is the focal length, v is the image distance, and u is the object distance. In this case, the object distance is given as 10.0 cm and the magnification is given as 4. Since the projected image is 4 times the size of the original object, the image distance is 4 times the object distance, which is 40.0 cm. Substituting the values into the lens formula, we get:

1/f = 1/40.0 - 1/10.0

Simplifying the equation, we find that f = 8.00 cm.