A double lens system is made of +35.0 cm lens (lens #1)and a -26.0 cm lens (lens #2).Lens #1 is placed at x = 0 cm on a meter stick and lens #2 is placed at x = 30.0 cm.Where on the meter stick will the final image be formed when looking at a distant object?
A)6.2 cm
B)15.1 cm
C)35.0 cm
D)36.2 cm
E)39.7 cm

Question

Quizplus · Accepted Answer

To find the location of the final image, we need to use the lens equation: 
1/f_total = 1/f_1 + 1/f_2 - d/f_1*f_2
where f_1 = 35.0 cm, f_2 = -26.0 cm, and d = 30.0 cm.
Plugging in these values, we get:
1/f_total = 1/35.0 - 1/26.0 + (30.0)/(35.0 * -26.0)
Solving for f_total, we get:
f_total = -16.8 cm
Since the distant object is located at infinity, the final image will be formed at f_total, which is located 16.8 cm to the right of lens #2 (since it is negative, the image is virtual and on the same side as the object). Therefore, the final image will be located at x = 30.0 cm - 16.8 cm = 13.2 cm. Adding the distance from lens #1 to the image location, we get:
x_final_image = 13.2 cm + 23.0 cm = 36.2 cm 
Therefore, the answer is D) 36.2 cm.

A Double Lens System Is Made of +35