# Quiz # 21_2

## Quiz # 21_2

#1
My # 37.35% Then...
100-37.35=62.65=0.6265
0.6265*(cos45)^2=0.31325*100=31.325%
working on the rest...

supr mo
Guest

## Q2

For number two, just do cos(theta)^2

guest768
Guest

## 3 and 4

Number 3
The distance between the third order 2-slit interference maxima on a screen 1.0928 meter from the slits which are 0.1097 mm apart is 3.48 cm. What is the wavelength of the light in nm (see sheet 20',21) ? Indicate with a positive (negative sign) whether you can (cannot) use the small angle approximation (see sheet 23) for the required accuracy of 1% in the quiz.

3.48E-2 / 2 = .0174
tan-1 (.0174/1.0928) = .912209303
(sin (.912209303) * .1097E-3) / 3 = 582nm

Number 4
In single slit diffraction the slit width is 0.1218 mm and the wavelength is 636 nm. Under which angle (in degrees) does the second order diffraction minimum occur (see sheet 25) ? Indicate with a positive (negative sign) whether at 00 a minimum (maximum) occurs.

(636E-9 * 2) / .1218E-3 = .010443349
sin-1 (.010443349) = .59837

krolik
Guest

## NUMBER 2

For number 2, simply doing cos (theta)^2 does not work, why not?

R
Guest

## QUESTION 2

ITS (COS^2) THETA FOR QUESTION 2

PHY
Guest

## number 2

#2 still wont work for me..

i did cos(62.16)^2 = .218
and then i did (cos(62.16))^2 = .218
and i even did cos (62.16^2) = .1068
and i tried them all as negative but i keep getting it wrong. im not getting the calculator syntax right

me
Guest

## I need help

I need help with 1 & 2

cutiepie
Guest

## #3 & #4

Even when I plug in the given values previously posted on the forum for 3 and 4, my numbers punched out in the calculator are so much larger. Like 25 instead of .xxxx. Am I using the wrong mode or something? Is there a setting i need to change to do these problems? I put it on degrees and then radians and still didnt get the correct answer.

k8
Guest

## #2

for #2..you do cos(theta)^2 x 100..thats ur ans (negative)

guest_01
Guest

## Re: Quiz # 21_2

how did you know to use 45 degrees for theta in the first question? thanks...

the dude
Guest

## question 3, i cant get it right

How do you do number 3 i tried doing the equation above and nothing....i even multiplied my answer by 10^-9

Guest786
Guest

## Question3

never mind i figured it out

Guest786
Guest

How do you do it

guest21
Guest

## Re: Quiz # 21_2

Nevermind I got it to

guest21
Guest

## number 2

The solution posted above is wrong, the conversion from mm to m is incorrect. It should be E-4 not E-3

yourmom
Guest

**number 3

yourmom
Guest

## Re: Quiz # 21_2

it's not wrong, it's a typo. Use the numbers in the problem.

krolik
Guest

#2 FINAL
Guest

123
Guest