a ray of light enters flint glass from air . the refractive index of flint glass with respect to air is given as 1.65 by what percent speed of light reduces on entering flint glass?
the reduction in percentage is neede to be find!
Refractive index ot medium A w r t medium B = speed in medium B/speed in medium A
w r t = with respect to,
1.65 = speed in air/speed in flint glass
speed in flint glass = 3 x 108/1.65 = 1.82x108 m/s
Percentage change in speed = (speed in flint glass - speed in air)x100/speed in air
= (1.82x108 - 3 x 108)x100/3 x 108 = -39.33%
Percentage reduction in speed = 39.33%