micole
posted by PHYSICS .
White light strikes a diffraction grating (930 lines/mm) at normal incidence. What is the longest wavelength that forms a secondorder maximum?
I used the equation [(1/d)sin(90)]/m = wavelength: [(1/0.93m)(1)] /2 = 0.5376m. To convert to nm I multiplied by 10^9. This is incorrect. Can anyone help? Thanks
Isn't d the reciprocal of 930/mm? or
or 1/d= .001m/930=1.08E8 m or .108nm?
check my thinking. In your equation, unit wise, if you are to have length on the right, you have to have length units on the left.
I remember the grading equation as
d sinTheta /n= lambda, where d is in meters.
Perhaps that is your error.

micole 
Jonathon
The answer should follow such that
Lines/mm > d > (1/930mm)/1000mm/m
d = 1.075e6 meters
set sin theta = 90o = (1)
(dsin(Theta))m=mlambda
(1.075e6 (1))/2)= 5.375e7 or 537nm.
Respond to this Question
Similar Questions

physics
Why is white light separated into a spectrum of colors when it is passed through a diffraction grating? 
PHYSICS
1) A diffraction grating with 2.500 x 10^3 lines/cm is used to examine the sodium spectrum. Calculate the angular separation of the two closely spaced yellow lines of sodium (588.995 and 589.592) in each of the first three orders. … 
physics
A diffraction grating gives a secondorder maximum at as angle of 31‹ for violet light (ƒÉ = 4.0 ~ 102 nm). If the diffraction grating is 1.0 cm in width, how many lines are on this diffraction grating? 
physics
A diffraction grating gives a secondorder maximum at as angle of 31‹ for violet light (ƒÉ = 4.0 ~ 102 nm). If the diffraction grating is 1.0 cm in width, how many lines are on this diffraction grating? 
Physics
Light of wavelength 600 nm illuminates a diffraction grating. The secondorder maximum is at angle 39.1°. How many lines per millimeter does this grating have? 
Physics
The light shining on a diffraction grating has a wavelength of 470 nm (in vacuum). The grating produces a secondorder bright fringe whose position is defined by an angle of 9.35°. How many lines per centimeter does the grating have? 
Physics
Diffraction grating #1 has half the lines/cm that diffraction grating #2 does. When used with a certain wavelength of light, both gratings give first order maxima. Which of the following statements is true for the same wavelength of … 
Physics, diffraction
1. Yellow light of wavelength 580 nm shines on a diffraction grating with 4000 lines/cm. A.At what angles do the firstorder and secondorder maxima occur? 
physics
An 11mm wide diffraction grating has rulings of 550 lines per mm. Light is incident normally on the grating. The longest wavelength that forms an intensity maximum in the fifth order is closest to? 
physics
An 11mm wide diffraction grating has rulings of 550 lines per mm. Light is incident normally on the grating. The longest wavelength that forms an intensity maximum in the fifth order is closest to?