Please help with the exercise

One day, after pulling down your window shade, you notice that sunlight is passing through a pinhole in the shade and making a small patch of light on the far wall. you see that the patch of light seems to be a circular diffraction pattern. it appears that the central maximum is about 1 cm across and you estimate that the distance from the window shade to the wall is about 3 m. what is (a) the average wavelength of sunlight? (b) the diameter of the pinhole?

Write the equation for momentum, first using symbols for the variables, then using words for the variables.

Clothes dryer uses about 7 amps of current from a 240 volt line. how much power does it use?