Final answer:
The boat moves toward the shore because the waves generated by the thrown rock transfer energy and momentum to the boat, causing it to oscillate and also carry it horizontally toward the shore due to the wave's energy transfer.
Step-by-step explanation:
The toy boat moves toward the shore because the waves transfer energy to it. When a rock is thrown into the pond, it creates waves that are periodic oscillations capable of transferring energy from the point of the rock's impact to other locations in the pond.
These waves travel outward and as they move under the boat, they cause it to move up and down. However, the energy from the waves can also move the boat horizontally toward the shore. This is a reflection of the nature of light and waves, where energy and momentum are transferred without the permanent transfer of mass.
Such a phenomenon is seen in the practical application where a buoy in the ocean converts the energy from waves into electricity. As the waves pass, the up-and-down motion of the buoy is transformed into rotational motion, which in turn generates power. The waves' ability to transfer energy and momentum is also analogous to how people create a wave effect in a sports stadium without physically moving from their spots.