How far are the goggles from the edge of the pool? - how far are the goggles from the edge of the pool
It is night, and they let the glass in a pool that is 5.0 m deep. If you have a laser pointer of 1.5 meters from the pool, the eyes can not illuminate when the laser beam, the water goes from 2.5 m from the edge.
How many drinks from the pool?
Sunday, January 24, 2010
How Far Are The Goggles From The Edge Of The Pool How Far Are The Goggles From The Edge Of The Pool?
1 comment:
You can use the law of Snell's why. Typical values of the refractive index of air and water are about 1.00 and 1.33, respectively. If n is the refractive index and Snell's Law:
s (sin) ((i) = n (w) sin r)
sin (r) = 0.75sin (i)
Where r is the angle of refraction and the angle of incidence (both relative to the perpendicular to the surface).
The laser beam passes through the water of 2.5 m from the edge, and their goal is 1.5 m above the water line. So:
tan (i) = 2.5/1.5 = 3 / 2 = 1.5
i = 56.3099 ° = 0.9828 rad
sin (i) = sin (0.9828) without (i) = 0.83205
sin (r) = 0.75sin (i) = 0.75 (0.83205) = 0.62404
r = 0.6739 rad = 38.61 °
Be the distance between the edge of the glasses:
d = 2.5 + 5tan (R) = 2.5 + 5 (0.79862) = 2.5 + 3.9931
d = 6.4931 m
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