Which of the following best defines "internal energy"? The energy associated with moving against a force. B. The sum of all the thermal and kinetic energies of a system. C. The transfer of energy due to a difference in temperature. D. The thermal energy required to increase the temperature of a system 1 oC.

B-The sum of all the thermal and kinetic energies of a system

Explanation:

Internal energy within a thermodynamic system is made up of two parts, potential and kinetic energy. The energy of the internal system will depend on the work done on the system and/or heat given off or absorbed. If heat is released the internal energy will decrease, and if heat is absorbed, the internal energy will increase.

radiation warms things up temp rises convection currents air circ windy weather

in physics zero. in muscle fatigue could be high