Trolley A is full of shopping, has a total mass of 8 kg and is moving at a velocity of 2 m/s with a kinetic energy of 16 J. Trolley B is empty, has a mass of 4 kg and is moving at a velocity of 0.5 m/with a kinetic energy of 0 5 J.

the old price per ounce is c/4.

the new price per ounce is c/3.6.

the ratio of the old price to the new one is

(c/4)/(c/3.6) = (c/c)×(3.6/4) = 0.9 . . = 9/10 . . "nine tenths" in either form

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.