Just imagine something like a single slit diffraction grating
and the distance x, you are looking for is the length between
the slit and viewing screen.
By proportionality,
Del y / x = Del p in y-direction / p in
x-direction
- (1)
Looking at the y-component, i.e. the slit separation,
d x del p in y-direction >= h / 4
pi
- (2)
Make (Del p in y-direction) the subject in (1) and sub into (2)
to get:
x = 4 pi (p in x-direction) (Del y) (d / h)
where your Del y = 1.00 x 10^-2 m, d = 2.00 x 10^-3 m (slit
diameter).
Solve for x to get 3.79 x 10^28 m.
P.S. Are you in my class?