Question on a Double Split Problem

  • Thread starter Thread starter StudentofPhysics
  • Start date Start date
  • Tags Tags
    Split
AI Thread Summary
The discussion revolves around calculating the distance between the third-order red fringe and the third-order yellow-green fringe in a double-slit experiment. The slits are 0.153 mm apart, with red light at 665 nm and yellow-green light at 565 nm, projected onto a screen 2.17 m away. The calculations initially yield a distance of 0.00043 m, which is later corrected to 0.0043 m. The confusion arises from a decimal placement error in the final result. The thread highlights the importance of careful calculations in physics problems.
StudentofPhysics
Messages
65
Reaction score
0
1. Two slits are 0.153 mm apart. A mixture of red light (wavelength = 665 nm) and yellow-green light (wavelength = 565 nm) falls on the slits. A flat observation screen is located 2.17 m away. What is the distance on the screen between the third-order red fringe and the third-order yellow-green fringe?

d= 0.153mm = 1.53 x 10^-3m
red wavelength= 665 nm = 6.65 x 10 ^-7 m
Yellow-green wavelength = 565 nm = 5.65 x 10^-7 m
x = 2.17m
m = 3




2. Sin theta = m (wavelength/d)



3. red:
Sin Theta = 3(6.65 x 10^-7) / (1.53 x 10^-3) = 0.0013m
Tan Theta = 0.0013 = y/x = y/2.17
red y= 0.00283

yellow-green:
Sin theta = 3 (5.65 x 10^-7) / (1.53 x 10^-3) = 0.0011
Tan theta = 0.0011 = y/x = y/2.17
yellow-green y= 0.0024


red y - yellowgreen y = .00283 - .0024 = 0.00043



This is not right for some reason.
What am I doing wrong?
 
Physics news on Phys.org
ok the answer was .0043, but I don't see where the decimal is wrong...
 
ok got it, nevermind.
 
I multiplied the values first without the error limit. Got 19.38. rounded it off to 2 significant figures since the given data has 2 significant figures. So = 19. For error I used the above formula. It comes out about 1.48. Now my question is. Should I write the answer as 19±1.5 (rounding 1.48 to 2 significant figures) OR should I write it as 19±1. So in short, should the error have same number of significant figures as the mean value or should it have the same number of decimal places as...
Thread 'A cylinder connected to a hanging mass'
Let's declare that for the cylinder, mass = M = 10 kg Radius = R = 4 m For the wall and the floor, Friction coeff = ##\mu## = 0.5 For the hanging mass, mass = m = 11 kg First, we divide the force according to their respective plane (x and y thing, correct me if I'm wrong) and according to which, cylinder or the hanging mass, they're working on. Force on the hanging mass $$mg - T = ma$$ Force(Cylinder) on y $$N_f + f_w - Mg = 0$$ Force(Cylinder) on x $$T + f_f - N_w = Ma$$ There's also...
Back
Top