Physics

Problem

A laser beam traveling in air (

n=1.00

) strikes a flat slab of crown glass (

n=1.52

) at an angle of

40^{\circ}

measured from the normal. Which of the following best describes the relationship between the incident angle

\theta_{\text{air}}

and the refracted angle

\theta_{\text{glass}}

? a)

\theta_{\text{glass}}>\theta_{\text{air}}

because light slows down in the glass. b)

\theta_{\text{glass}}<\theta_{\text{air}}

only if

\theta_{\text{air}}

exceeds the critical angle. c)

\theta_{\text{glass}}<\theta_{\text{air}}

because light slows down in the glass. d)

\theta_{\text{glass}}=\theta_{\text{air}}

because the interface is planar.