A boulder has 300 J of potential energy sitting on the edge of a cliff. What is the boulder's kinetic energy as it hits the ground?
Why would it not be 300J?
To determine the boulder's kinetic energy as it hits the ground, we need to consider the principle of conservation of energy. According to this principle, the total energy of a closed system remains constant, meaning that energy cannot be created or destroyed, only transferred or transformed between different forms.
In this scenario, the potential energy of the boulder on the edge of the cliff is being converted into kinetic energy as it falls. The equation that relates potential energy to kinetic energy is:
Potential Energy + Kinetic Energy = Total Mechanical Energy
Given that the potential energy is 300 J, we can set up the equation as follows:
300 J + Kinetic Energy = Total Mechanical Energy
Since the boulder eventually hits the ground, all of its potential energy is converted into kinetic energy, resulting in the total mechanical energy being equal to the kinetic energy alone.
Therefore, the boulder's kinetic energy as it hits the ground is 300 J.