Q4. Olly Murs pushes a car uphill. He pushes with a force of 2.5kN over a distance of 2.5m.
Calculate the work done by his muscles.

Light from a sodium lamp passes through a diffraction grating that has 1000 slits per millimeter. the interference pattern is viewed on a screen 1.000 m behind the grating. the first (m = 1) two bright yellow fringes that are visible are 0.7288 m and 0.7300 m from the central maximum. what are the wavelengths of these two fringes?