Answer: 6.7 cm
Step-by-step explanation:
Given: Height of object= 14 cm
Distance of object from the concave lens u=-20 cm
Focal length of concave lens= -10 cm
Lens formula is given by,
\(\frac{1}{f}=\frac{1}{v}-\frac{1}{u}\)
\(\Rightarrow\frac{1}{v}=\frac{1}{f}+\frac{1}{u}\)
To find Image distance from the lens v, we substitute values of 'u' and f in the lens formula , we get
\(\Rightarrow\frac{1}{v}=\frac{1}{-10}+\frac{1}{-20}\\\\\Rightarrow\frac{1}{v}=-(\frac{1}{10}+\frac{1}{20})\\\\\Rightarrow\frac{1}{v}=-\frac{2+1}{20}\\\\\Rightarrow\frac{1}{v}=-\frac{3}{20}\\\\\Rightarrow\ v=\frac{20}{3}=6.6666\approx6.7\)
Thus, The distance of the image from the lens, rounded to the nearest tenth, is 6.7 cm.
