Final answer:
The statement is false; stress and internal energy are not the same. Stress is related to force per area, while internal energy includes the kinetic and potential energies within a material.
Step-by-step explanation:
The statement 'Stress is the intensity of internal energy' is false. Stress in a physical and engineering context refers to the force exerted on a material per unit area. In contrast, internal energy pertains to the total energy contained within a system, which is attributed to the kinetic and potential energy of molecules.
Some common misconceptions are addressed in the other true or false questions provided:
- Throwing a rock into the air increases its potential energy, not kinetic energy, when it gains height. The kinetic energy increases as it falls back to the ground.
- An external force is indeed necessary to set a stationary object in motion in space because inertia must be overcome.
- The force that opposes gravity is called the normal force, and it works perpendicular to the surface contact, not in the direction of gravity.