An object falls freely from rest on a planet where the acceleration due to gravity is 22m/s^2 after 9.5s what will be it’s speed?

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