A strange science-fiction battle takes on a tiny moon in deep space; here, the moon is so small that we can completely ignore gravity. A deranged invading space monster of given mass 28.2 kg kicks off a rocky structure to achieve a horizontal speed of 3.45 m/s directly toward a startled space cadet. The cadet is braced firmly on the surface of the moon and is armed with a rapid-fire automatic marshmallow blaster gun which fires multiple sticky marshmallows toward the monster, each of mass 11.5 grams and each with a speed of 53.4 m/s. The cadet attempts to stop the monster with the marshmallow gun, slowing the monster down by hitting the monster with marshmallow after marshmallow until the monster is finally brought to a stop. How many marshmallows will the cadet have to fire at the monster to stop the monster's horizontal motion? (Assume each fired marshmallow harmlessly sticks to the monster. Assume that the monster is flying horizontally, with no vertical motion and no friction or other forces on the monster except for those due to the collision with the marshmallows. Explain your work. Indicate what Physics Concept (law of physics) you used to solve this