Answer:
6.67 cm
Step-by-step explanation:
Given
- h (image) = 4 x h (object)
Finding magnification
- m = h (image) / h (object)
- m = 4 x h (object) / h (object)
- m = + 4.0
Finding image distance
- m = - (image distance / object distance)
- 4 = - (v / 5)
- 4 = -v/5
- v = -20
- v = -20 cm
Mirror formula
Solving
- 1/f = 1/-20 + 1/5
- 1/f = -1 + 4/20
- 1/f = 3/20
- f = 20/3 cm
- f = 6.67 cm