Answer:
7.08 m
Explanation:
(If we ignore the refraction of light)
There will form two triangles one at the top of pool (torch, edge of pool and point of incidence at top of pool) and one at the bottom of pool (torch, edge of pool and point of incidence at bottom of pool) .
first triangle at the top of pool (torch, edge of pool and point of incidence at top of pool)
First we need to find the angle of incidence:
Height = perpendicular = 1.3 m
Point of incidence = base= 2.5 m
now
tan∅= perpendicular / base
∅= tan⁻¹ (perpendicular / base)
∅=tan⁻¹ (1.3/2.5)
∅= 27.5°
Now 2nd triangle at the bottom of pool (torch, edge of pool and point of incidence at bottom of pool)
Height = perpendicular = 1.3 m + 2.1 m= 3.4 m (torch height + depth of pool)
∅= 27.5°
Spot of light hit bottom of pool= base=?
tan∅ = perpendicular / base
base = perpendicular / tan∅
base = 3.4/tan(27.5°)
base= 7.08 m
Spot of light hit bottom of pool= base= 7.08 m
