Mrs. Canales pointed to an apple sitting on her desk. She asked her students to describe any forces acting
on the apple. This is what some of her stu-
dents said.
Archie: "The only force acting on the
apple is air pressure."
Sam: "There is one force acting on the apple. Gravity is the force that pulls on
the apple."
Soledad: "There are two forces: the desk pushes up on the apple and gravity pulls
downward on the apple."
Misha: "There are many forces acting on the apple; but, it is the holding force in the
apple that keeps it on the desk."
Tess: "There are no forces acting on the apple because the desk stops any forces
from acting on it."
Which student do you most agree with?