University of Central Florida (UCF) PSC1121 Physical Science Final Practice Exam

A can of Pepsi at rest on a table experiences two primary forces acting upon it: gravitational force and the normal force (also referred to as the rigidity force in this context) from the table. The gravitational force pulls the can downward toward the center of the Earth, while the tabletop provides an upward force that supports it, preventing it from accelerating downward.

When the can is stationary, these two forces are balanced, meaning they have equal magnitude but opposite directions. In this case, if the gravitational force acting on the can is stated to be 3.822 N downward, the corresponding normal force exerted by the table must also equal 3.822 N but acts in the opposite direction (upward). This balance of forces is a demonstration of Newton's first law of motion, which states that an object at rest will remain at rest unless acted upon by a net external force.

Thus, the option that states both the downward gravitational force and the upward rigidity (normal) force from the table is correct because it accurately reflects the conditions of force equilibrium acting on the can at rest.