Final answer:
The behavior of waves is complex; a pebble causing a pulse wave is true, waves with different frequencies can superimpose, which is also true, and the statement about energy exchanges when throwing a rock is false.
Step-by-step explanation:
The student has asked several questions related to the behavior of waves, which falls under the subject of Physics. To address the questions at hand:
- A pebble dropped in water is indeed an example of a pulse wave, making the statement true.
- It is also true that waves can superimpose if their frequencies are different.
- When considering the scenario where a rock is thrown into the air, the statement is false because an increase in height increases the potential energy, not the kinetic energy, and an increase in velocity as it falls to the ground increases its kinetic energy, not potential energy.
These principles help us to understand the dynamic behavior of waves as they interact with each other and their environment, such as when water waves crash against obstructions like rocks or seawalls.