Assuming the acceleration is still -9.81 m/s 2 , what is the instantaneous velocity of the shuttlecock when it hits the ground

answer(20) psi;

one "light year" is the distance that light travels, through vacuum, in one julian year.   that's 365.25 days, of 24 hours each.

no. bullets are macro objects. wave nature is for light waves, extremely tiny particles. if a light particle was the size of your finger, the bullet would be the size of the universe. so basically, that huge difference in size makes the wave nature of matter insignificant.