A book is at rest on fire table of the book is pushed across the table, causing it to move, and eventually come to rest again how does a potential and kinetic energy change during its process?
When a book is at rest on a table, it has a certain amount of potential energy due to its position above the ground. This potential energy can be converted into kinetic energy when the book is pushed and starts moving. As the book moves across the table, its potential energy decreases because it is getting closer to the ground, while its kinetic energy increases because it is gaining speed and motion. Once the book comes to rest again, its kinetic energy is completely converted back into potential energy due to its elevated position above the ground. Therefore, during this process, the potential energy decreases and the kinetic energy increases until the book comes to rest again and the kinetic energy is completely converted back into potential energy.
During the process described, the potential and kinetic energy of the book undergo several changes. Let's break it down step-by-step:
1. Initial state: The book is at rest on the table. It possesses potential energy due to its position above the ground. However, it has no kinetic energy since it is not in motion.
2. Pushing the book: When the book is pushed, an external force acts on it, doing work and transferring energy to the book. This work increases the book's kinetic energy, causing it to start moving across the table. As the book gains speed, its kinetic energy increases, while its potential energy decreases because it is moving closer to the ground.
3. Moving on the table: As the book continues to slide across the table, its kinetic energy remains constant if there is no additional force acting on it and no work being done on it. If air resistance or friction from the table is present, some of the book's kinetic energy would decrease and be converted into other forms like heat or sound.
4. Coming to rest: Eventually, the book will come to rest again, either due to internal friction within the book or external factors like increased air resistance. As the book slows down and comes to a stop, its kinetic energy decreases until it reaches zero. At the same time, its potential energy increases as it moves away from the ground, regaining its initial position.
Overall, the potential energy of the book decreases and then increases to its original value, while its kinetic energy increases initially, remains constant (ideally) during motion, and then decreases back to zero once it comes to rest.