A person throws a ball up into the air, and the ball falls back toward Earth. At which point would the kinetic energy be the lowest? (1 point)
An object falls through the air, gaining speed as it falls. A student claims that this creates new energy, and so it breaks the law of conservation of energy. Which statement describes why the student is incorrect? (1 point)
The kinetic energy of the ball would be the lowest at the highest point of its trajectory, just before it starts falling back towards the Earth.
The student is incorrect because the increase in speed and kinetic energy of the falling object is a result of the conversion of potential energy (due to its initial height) into kinetic energy. This process does not violate the law of conservation of energy as the total energy (potential + kinetic) remains constant.
1. The kinetic energy of the ball would be the lowest at the highest point of its trajectory. This is because as the ball reaches its highest point, it has lost most of its initial kinetic energy and gained potential energy due to its increased height above the ground. As it falls back toward Earth, potential energy is converted back into kinetic energy, resulting in an increase in kinetic energy.
2. The student is incorrect because the process of the object falling through the air and gaining speed does not create new energy. According to the law of conservation of energy, energy cannot be created or destroyed, but can only be converted from one form to another. In this case, as the object falls, potential energy is converted into kinetic energy, but no new energy is created. The total amount of energy remains constant.