The correct option is **C. Potential energy**. ### Explanation of the Correct Answer **Potential Energy Defined:** Potential energy is the energy stored in an object due to its position or configuration. In the context of a gravitational field, potential energy is specifically related to the height of an object above a reference point, usually the ground. The higher an object is positioned, the more gravitational potential energy it possesses. **Formula for Gravitational Potential Energy:** The gravitational potential energy (U) can be calculated using the formula: \[ U = mgh \] Where: - \( U \) = gravitational potential energy (in joules, J) - \( m \) = mass of the object (in kilograms, kg) - \( g \) = acceleration due to gravity (approximately \( 9.81 \, \text{m/s}^2 \) on the surface of the Earth) - \( h \) = height of the object above the reference point (in meters, m) **Step-by-Step Explanation:** 1. **Understanding Position in a Gravitational Field:** - An object in a gravitational field experiences a force due to gravity. This force acts downward towards the center of the Earth (or another massive body). - When an object is lifted to a height \( h \), work is done against the gravitational force, and this work is stored as potential energy. 2. **Example Calculation:** - Consider a 2 kg object lifted to a height of 5 meters. The potential energy can be calculated as follows: \[ U = mgh = (2 \, \text{kg}) \times (9.81 \, \text{m/s}^2) \times (5 \, \text{m}) = 98.1 \, \text{J} \] - This means the object has 98.1 joules of gravitational potential energy at that height. 3. **Energy Transformation:** - If the object is released, the potential energy converts into kinetic energy as it falls. This transformation illustrates the relationship between potential and kinetic energy. ### Explanation of Incorrect Options **A. Kinetic Energy:** - Kinetic energy is the energy of motion. It is given by the formula: \[ KE = \frac{1}{2} mv^2 \] Where \( v \) is the velocity of the object. Kinetic energy is not associated with position but rather with the speed and mass of an object in motion. Therefore, it does not relate to the position or configuration in a gravitational field. **B. Thermal Energy:** - Thermal energy is the energy that comes from the temperature of an object. It is related to the kinetic energy of the particles within the substance. While thermal energy can be influenced by gravitational potential energy (e.g., in hydroelectric dams), it is not primarily associated with the position of an object in a gravitational field. **D. Chemical Energy:** - Chemical energy is the energy stored in the bonds of chemical compounds. It is released or absorbed during a chemical reaction. This form of energy is not related to the position of an object in a gravitational field but rather to the arrangement of atoms and molecules. ### Common Pitfalls - Confusing potential energy with kinetic energy: Remember that potential energy is about position, while kinetic energy is about motion. - Misunderstanding the role of height: Potential energy increases with height in a gravitational field, so always consider the height when calculating gravitational potential energy. ### Revision Summary - **Potential energy** is the energy stored due to an object's position in a gravitational field. - The formula for gravitational potential energy is \( U = mgh \). - Kinetic energy relates to motion, thermal energy relates to temperature, and chemical energy relates to molecular bonds, making them incorrect options in this context. - Always remember the relationship between potential and kinetic energy during energy transformations.