Final answer:
The statement that peridotite is less dense than basalt is false; peridotite is usually denser. Also, as a rock is thrown into the air, its potential energy increases, and kinetic energy decreases, contrary to the statement in the question.
Step-by-step explanation:
The statement that peridotite is less dense than basalt is false. Peridotite is an ultramafic rock made mostly of iron- and magnesium-rich silicate minerals, which makes it quite dense. In fact, peridotite is usually more dense than basalt, which is why peridotite is found in the Earth's mantle and basalt is found in the Earth's crust. The Earth's mantle is known to be extremely hot and is part of what contributes to the movement of tectonic plates due to its physical properties.
Concerning the second question about the relationship between kinetic energy, potential energy, and height for a thrown rock, the statement is false. As a rock is thrown into the air, its potential energy increases with height while its kinetic energy decreases. Conversely, as the rock falls back to the ground, its potential energy decreases, and its kinetic energy increases due to acceleration by gravity.