Help with some practice questions please

1. Dec 3, 2008

mmmboh

1. The problem statement, all variables and given/known data

In a single slit experiment the slit width is 100 times the wavelength used.
1)find the width of the central maximum on a screen 3m behind the slit.
2)Find the width of the first order secondary maximum.
3) Find the intensity I in terms of the maximum intensity Io at angle 2 degrees.

2. Relevant equations

sin theta=m(lamda)/a
dsin theta=m(lamda)
sin theta1=1.22lamda/D
Ym=xm(lamda)/a
I=Io(((sin(B/2))/(B/2))^2
I=Io((sin(pi x a(sin theta))/(lamda))/(pi x a (sin theta)/lamba))^2

3. The attempt at a solution[/b

1)Using Ym=xm(lamda)/a
I would do Ym=3lamda/100lamda, so ym=0.03 m....is that right?

2)I think I use this formula Ym=xm(lamda)/a....I'm not sure though :S

3)For this one I would obviously use the equation I=Io(((sin(B/2))/(B/2))^2, or I=Io((sin(pi x a(sin theta))/(lamda))/(pi x a (sin theta)/lamba))^2...however in either case I do not know what either lamda, nor what B is.

I know I suck, I've been reviewing because I have a test soon and I have a lot of work and don't have time to get help from a teacher. Any help would be appreciated :)