Explanation:
Given that,
The mass of rock, m = 2.35-kg
It was released from rest at a height of 21.4 m.
(a) The kinetic energy is given by : 
As the rock was at rest initially, it means, its kinetic energy is equal to 0.
(b) The gravitational potential energy is given by : 
It can be calculated as :

(c) The mechanical energy is equal to the sum of kinetic and potential energy such that,
M = 0 J + 492.84 J
M = 492.84 J
Hence, this is the required solution.
Answer:
Balanced.
Explanation:
A Balanced Chemical equation is a scientific term that describes a chemical equation that has the same number of atoms on each side of the equation.
Hence, when the number of atoms on the right side of a chemical equation matches the number of atoms on the left side of a chemical equation, it is said to be BALANCED.
Answer:
Ptolemy made geocentric model of the solar system using epicycles
Explanation:
Ptolemy made geocentric model of the solar system using epicycles.
This model accounted for the apparent motions of the planets in a very direct way, by assuming that each planet moved on a small circle, called an epicycle, which moved on a larger circle, called a deferent.
Therefore, Ptolemy is the answer.
Answer: Their temperature decreases dramatically, but their luminosity increases only slightly.
Explanation: Edmentum answer