1. The problem statement, all variables and given/known data Quantum effects are negligible in "macroscopic" world. Show than on example. A tennis ball with speed 0.5 m/s is thrown thru a window. Dimensions of a window are 1*1.5 m. Calculate vertical and horizontal diffraction angles. 2. Relevant equations [tex]\lambda[/tex]=h/p dSin[tex]\alpha[/tex]=n[tex]\lambda[/tex] 3. The attempt at a solution For horizontal diffraction angle. [tex]\lambda[/tex]=h/mv=h/m*0.5 I assumed that n=1. so dSin[tex]\alpha[/tex]=n[tex]\lambda[/tex]=h/m*0.5 [tex]\alpha[/tex]=ArcSin(h/m*0.5*d)=ArcSin(h/m*0.5*1) from this I would conclude thath, alpha is negligible small, that is quantum effect are negligible. I would do the same thing for vertical angle. I' not shure if I'm right ?