Answer :
Answer:
The focal length of the mirror is 52.5 cm.
Explanation:
Given that,
Object to Image distance d = 140 cm
Image distance v= 35 cm
We need to calculate the object distance
[tex]u = d-v[/tex]
[tex]u = 140-35=105\ cm[/tex]
We need to calculate the focal length
Using formula of mirror
[tex]\dfrac{1}{f}=\dfrac{1}{u}+\dfrac{1}{v}[/tex]
Put the value into the formula
[tex]\dfrac{1}{f}=\dfrac{1}{-105}+\dfrac{1}{35}[/tex]
[tex]\dfrac{1}{f}=\dfrac{2}{105}[/tex]
[tex]f=52.5\ cm[/tex]
Hence, The focal length of the mirror is 52.5 cm.