Which is the variable that the experimenter changes

muscle endurance

explanation:

i can do 50 in a row ( but i get so tired after that)

answer is slate

hope this

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.