Which statement best describes how the intensity of the wave depends on position along the screen when the slit width is approximately the same as the wavelength of the light? a. The intensity is roughly constant along the viewing screen.
b. The intensity is at a maximum near the middle of the screen (along the central axis) and has alternating areas of higher and lower intensity with the intensity generally decreasing as the distance from the middle of the screen increases.
c. The intensity is large near the middle of the screen then decreases to nearly zero as the distance from the middle of the screen increases.

As you are trying to move a heavy box of mass m, you realize that it is too heavy for you to lift by yourself. there is no one around to , so you attach an ideal pulley to the box and a massless rope to the ceiling, which you wrap around the pulley. you pull up on the rope to lift the box. use g for the magnitude of the acceleration due to gravity and neglect friction forces. once you have pulled hard enough to start the box moving upward, what is the magnitude f of the upward force you must apply to the rope to start raising the box with constant velocity? express the magnitude of the force in terms of m, the mass of the box.