Final answer:
It is false that watertight flashlights meet the navigational light standards for vessels. True answers are affirmed for solar sails using solar wind for propulsion, pulse waves being created by pebbles in water, and lightning being able to travel through wood. Moreover, the photoelectric effect is not limited to visible light, and refraction plays a crucial role in the functioning of fiber optic cables.
Step-by-step explanation:
Navigation Lights and Watertight Flashlights
It is false that watertight flashlights can be used as navigation lights for unpowered and sailing vessels. Navigation lights have specific color, position, and visibility requirements as per maritime regulations to ensure that vessels are seen at night or in poor visibility conditions to prevent collisions. Using a standard watertight flashlight would likely not meet these criteria.
Solar Sail Craft Propulsion
The statement that a solar sail craft can be propelled using just particles within the solar wind is true. Solar sails are designed to capture the momentum of photons from the Sun's rays or solar wind particles, providing thrust without the need for a conventional propellant.
Photoelectric Effect and Electromagnetic Radiation
The statement that visible light is the only type of electromagnetic radiation that can cause the photoelectric effect is false. The photoelectric effect can be caused by any electromagnetic radiation that has a frequency high enough to eject electrons from a material.
Pulse Waves and Pebbles
It is true that a pebble dropped in the water is an example of a pulse wave. A pulse wave is a single disturbance that moves through a medium, and dropping a pebble into water creates such a disturbance.
Lightning Traveling Through Wood
It is true that although wood is generally an insulator, lightning can travel through a tree to reach Earth. The intense energy and heat of lightning can cause a sudden surge of current through materials that are normally insulators, like wood.
Refraction in Fiber Optic Cables
The statement that refraction is useful in fiber optic cables for transmitting signals is true. Refraction is the bending of light as it passes from one medium to another, and it is essential to the operation of fiber optic cables, allowing light to be guided along the cable with minimal loss of signal.