Question 18 (1 point)
Rita climbs a ladder to the top of a water slide, waits her turn, and then slides down the slide into a pool. Which series describes the energy changes of her actions?
a
potential → mechanical → kinetic
b
kinetic → mechanical → potential
c
potential → kinetic → potential
d
kinetic → potential → kinetic
a) potential → mechanical → kinetic
The correct answer is:
c) potential → kinetic → potential
Explanation:
When Rita climbs the ladder to the top of the water slide, her energy is in the form of potential energy as it is stored due to her position at a height. When she slides down the slide, her potential energy is converted into kinetic energy as she gains motion. Finally, when she enters the pool and comes to a stop, her kinetic energy is converted back into potential energy as she reaches a lower position in the pool.
To determine the correct answer, we need to understand the different types of energy involved in this scenario.
1. Potential energy refers to the stored energy of an object based on its position or condition. In this case, when Rita climbs the ladder, her potential energy increases as she gains height.
2. Mechanical energy is the sum of an object's potential and kinetic energy, considering both its position and motion.
3. Kinetic energy relates to the energy of an object in motion. As Rita slides down the water slide, her potential energy is converted into kinetic energy.
Based on this understanding, let's analyze the series options:
a) potential → mechanical → kinetic:
This option correctly describes the energy changes. As Rita climbs the ladder, her potential energy increases (potential) which is then converted to a combination of potential and kinetic energy (mechanical) when she is on top of the water slide. Finally, when she slides down, her potential energy is transformed entirely into kinetic energy (kinetic) as she gains motion.
b) kinetic → mechanical → potential:
This series is incorrect because it suggests that kinetic energy is present before the mechanical energy. However, kinetic energy depends on both position and motion, so it cannot occur before mechanical energy is established.
c) potential → kinetic → potential:
This series is also incorrect. It suggests that Rita's potential energy turns into kinetic energy and then back into potential energy. However, once her potential energy is converted into kinetic energy, it cannot revert back to potential energy in this scenario.
d) kinetic → potential → kinetic:
This series is incorrect because it indicates that kinetic energy occurs before potential energy. However, potential energy must be present initially (when Rita climbs the ladder) before it's converted into kinetic energy.
Hence, the correct answer is a) potential → mechanical → kinetic.