Answer:
- 58 cm
Explanation:
refractive index, n = 1.6
radius of curvature of left face, R1 = - 65 cm
Radius of curvature of the right face, R2 = 75 cm
Use the lens maker's formula
[tex]\frac{1}{f}=\left ( n-1 \right )\times \left ( \frac{1}{R_{1}}-\frac{1}{R_{2}} \right )[/tex]
[tex]\frac{1}{f}=\left ( 1.6-1 \right )\times \left ( -\frac{1}{65}-\frac{1}{75} \right )[/tex]
[tex]\frac{1}{f}=\left ( 0.6 \right )\times \left ( \frac{-75-65}{75\times 65}\right )[/tex]
f = - 58 cm
Thus, the focal length of the lens is - 58 cm.
