A quarterback throws a football toward a receiver with an initial speed of 20 m/s at an angle of 30∘ above the horizontal. At that instant the receiver is 20 m from the quarterback. In (a) what direction and (b) with what constant speed should the receiver run in order to catch the football at the level at which it was thrown?

The goal of this experiment was to answer the question, "how does diffraction occur? " suppose you formulated this alternate hypothesis: if the gap width is increased while keeping wavelength constant, then the observed diffraction will decrease because the less the ratio between wavelength and gap width is, the smaller the observed diffraction angle will be. to test this hypothesis, you would change the  gap widthdiffraction anglewavelength  and observe the  gap widthdiffraction anglewavelength  in the system. therefore, the independent variable would be the  gap widthdiffraction anglewavelength  and the dependent variable would be the  gap widthdiffraction anglewavelength.