The position of the image is determined as 30 cm behind the mirror. (Option D).
How to calculate the image position?
The position of the image is calculated by applying the following formula;
1/f = 1/u + 1/v
where;
- f is the focal length of the concave mirror
- u is the position of the object
- v is the position of the image
The given parameters include;
the focal length, f = 20 cm
the position of the object, u = 60 cm
The position of the image is calculated as;
1/20 = 1/60 + 1/v
1/v = 1/20 - 1/60
1/v = (3 - 1)/60
1/v = 2/60
v = 60 / 2
v = 30 cm