Class Management Help HW 6 Begin Date: 10/16/2017 12:00:00 AM -- Due Date: 10/24
ID: 1785972 • Letter: C
Question
Class Management Help HW 6 Begin Date: 10/16/2017 12:00:00 AM -- Due Date: 10/24/2017 11:59:00 PM End Date: 12/16/2017 12:00:00 AM (8%) Problem 11: A laser beam has a velocity in vacuum of c = 3 × 108 m/s. A student runs an experiment in which a liquid is placed in a tank of length L = 11 m. The time it takes for the beam to make it across the tank is timed to be t=53 ns 50% Part (a) Write an expression for the liquid's index of refraction, n 50% Part (b) Numerically, what is this index? Grade Summary 0% 100% Potential tan() | acos0 Submissions Attempts remaining: Z (5% per attempt) detailed view HOME cosO Sin cotan atan()acotan cosh0tanh0cotanh) sinh) 0 END o Degrees Radians BACKSPACE DELCLEAR Submit Hint I give up! Hints: 1 % deduction per hint. Hints remaining: 2 Feedback: 1% deduction per feedbackExplanation / Answer
Let the Laser be incident on the surface at an angle 90 degrees and after refraction let the angle be
hence by definition,refractive index, n= sin(90) / sin()
sin()=1/n, cos()=sqrt(n2-1) / n
now after the refraction,
distance travelled by light, l =11/cos()
we know, distance= speed*time
11/cos()=c*53*10-9=3*108*53*10-9
1/cos()=1.445
putting the value of cos() above,
1.445=n / sqrt(n2-1)
n=1.801