Which of the following terms refers to the flow of energy, heat, and work?

If a stone with an original velocity of 0 is falling from a ledgeand takes 8 seconds to hoybthe ground whays the final velocity of the stone

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?

If anyone who can me with this hw? i would really appreciate it