Using the graph, describe what is happening between 4 and 6 seconds. the object is moving away from the origin at a constant velocity. the object is not moving. the object is moving toward the origin at a constant velocity. the object is changing velocity.

Which of the following best describes internal energy? a. the difference between the kinetic and potential energies of the particles in a system b. the sum of the kinetic and potential energies of the particles in a system c. the sum of the kinetic and thermal energies of the particles in a system d. the difference between the kinetic and thermal energies of the particles in a system