Understanding the Concepts
* Conservation of Energy: The total mechanical energy of the baseball (potential energy + kinetic energy) remains constant throughout its flight, neglecting air resistance.
* Potential Energy: This is the energy stored in an object due to its position. For the baseball, potential energy is highest at its peak and lowest at the ground.
* Kinetic Energy: This is the energy of motion. It's highest when the baseball is moving fastest (at the start and just before hitting the ground).
The Solution
1. Ignoring Air Resistance: We'll assume air resistance is negligible for this problem. This simplifies the calculation significantly.
2. At the Highest Point: At the baseball's highest point, its velocity is momentarily zero (it stops before falling back down). All its initial kinetic energy has been converted to potential energy.
3. Back to the Ground: As the baseball falls, potential energy is converted back into kinetic energy. Since energy is conserved, the kinetic energy at the ground will be equal to the initial kinetic energy.
4. Same Speed, Opposite Direction: Because the baseball's kinetic energy is the same at the start and end, its speed will also be the same. However, the direction will be reversed.
Therefore, the speed of the baseball when it hits the ground will be 150 meters per second.
