Which form of energy is measured in joules?

The correct answer is potential energy. It is a form of mechanical energy that is stored in an object due to its position or condition. Potential energy is measured in joules, which is the standard unit of energy in the International System of Units (SI). The concept of potential energy is integral in physics, especially in understanding how energy is stored and released in various systems, such as gravitational potential energy in an elevated object or elastic potential energy in a compressed spring.

Other forms of energy, such as kinetic energy (associated with the motion of an object), thermal energy (related to the temperature and motion of particles in a substance), and nuclear energy (derived from nuclear reactions), are also measured in joules. However, potential energy specifically pertains to stored energy based on an object's position, highlighting its unique role in the broader context of energy types.