Start by writing the equation you will be using $($include what you are calculating on the left side of the equal sign$)$ then plug in the explicitly the numbers used in the formula, finally calculate indude the correct unit fro each frat arswer.

For more details, see instruction on page $2$ of this exam paper.

The distance between slits in a grating is $3600$ nm $,$ and the width of each slit is $900$ nm $.$ A laser beam is shone on the grating and an interference$/$diffraction pattem is observed on a screen $1\mathrm{.}2$ m away from the grating as illustrated by the grev panel on the diagram below. Note: $1nm={10}^{-9}m={10}^{-7}cm.$

a$.$ The first bright dot