Recall Snell's law, c1/c2=sin theta 1/sin theta 2, where c1 is the speed of light in one medium, c2 is the speed of light in a second medium, and theta1 and theta2 are the angles. Suppose a light is shining through the water into the air. As theta1 increases, theta2 approaches 90 degrees, at which point no light will emerge from the water. Assume the ratio c1/c2 in this case is .752. For what value of theta1 does theta2=90 degrees? This value is called the critical angle for water.[/i]
Please help, I have no idea where to start.
Please help, I have no idea where to start.