Answer:
Focal length is 6.67 cm.
Explanation:
Object distance, u, from the lens = 10 cm
Image distance, v, to the lens = 10 cm + 10 cm
= 20 cm
Apply the lens formula to determine the focal length, f, of the lens.
[tex]\frac{1}{f}[/tex] = [tex]\frac{1}{u}[/tex] + [tex]\frac{1}{v}[/tex]
= [tex]\frac{1}{10}[/tex] + [tex]\frac{1}{20}[/tex]
= [tex]\frac{2 + 1}{20}[/tex]
[tex]\frac{1}{f}[/tex] = [tex]\frac{3}{20}[/tex]
Find the inverse of both sides, so that;
f = [tex]\frac{20}{3}[/tex]
= 6.67
f = 6.67 cm
The focal length of the lens is 6.67 cm.
