Final answer:
Thermal energy can be determined by measuring an object's temperature, which reflects the internal kinetic energy of the particles within it. Calorimetry is used for precise measurement of thermal energy transfer by observing changes in temperature.
Step-by-step explanation:
The question 'How do you determine the thermal energy of an object?' is best answered by explaining that thermal energy is akin to the internal kinetic energy that comes from the random motion of particles in a substance. To determine the thermal energy, one can measure the temperature of the object, which is proportional to the average kinetic energy of its atoms and molecules. When these particles move or vibrate more rapidly, the object has a higher average kinetic energy and is perceived as 'hotter.' If the particles have slower motion, it has lower average kinetic energy, meaning the object is 'colder.'
For more precise measurements, especially in chemical or physical processes, calorimetry is used. This technique measures the amount of thermal energy transferred by observing the temperature change that occurs. By using the specific heat and mass of the object, along with the recorded temperature change, one can calculate the exact amount of thermal energy transferred, usually expressed in joules or calories.