How might what is happening in this image affect the nervous system?

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

Which of the following forces require physical contact? tension air resistance friction magnetic force applied force

If you let go of the notebook after lifting it, will it move? how?