Answer:
Ptolemy proposed a model, he reference system is centered on the Earth
Copernicus, proposed a deferent system, this system is centered on the Sun, where it is at the origin of the system
Explanation:
Thousands of years ago, Ptolemy proposed a model to explain the movement of the planets and stars in the sky, in this model the reference system is centered on the Earth, so each body is orbiting in different spheres around the Earth as its center, this system had very complicated calculations and curves to be able to explain the orbits of the planets.
More recently Copernicus, proposed a deferent system, this system is centered on the Sun, where it is at the origin of the system, in this system the movement of the planets are ellipses, which is a much simpler explanation and has been widely accepted, in current systems the reference system is fixed in the bodies more massive, since this simplifies the explanation of the movements.
Answer:
charged pith ball works well to show the Coulomb force between two charged objects. If a glass rod is rubbed with silk, the silk rubs some electrons off the rod. The rod thus becomes positively charged. ... Since like charges repel, the pith balls repel one another.
Explanation:
Answer:
Part a)

Part b)

Explanation:
Part a)
As we know that the diameter of the planet is given as

now the radius of the planet is given as

now we know that the acceleration due to gravity of the planet is given by the equation

here we know that

now from above equation we have

now we have

Part b)
Now by kepler's law we know that
time period of revolution of planet about the star is given as

so we have

now we have


mula of time period

Now we have

For this experiment on a solar collector, the variables include the following:
<h3>What are the variables?</h3>
In Science, a variable can be defined as a measurable attribute or physical quantity that changes or varies across an experiment and as such can take on different numerical values.
For this experiment on a solar collector, there are different variables and these include the following:
Furthermore, you should determine both the greatest and smallest rate of temperature change for each of the trials by subtracting the initial temperature from the final temperature based on the numerical values obtained from this experiment.
In conclusion, the trial with the greatest numerical value has the greatest rate of temperature change while the trial with the smallest numerical value has the smallest rate of temperature change
Read more on variables here: brainly.com/question/632913
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<u>Complete Question:</u>
1. What are the variables in this investigation?
2. Which trial had the greatest rate of temperature change?
3. Which trial had the smallest rate of temperature change?
Answer:
a) When its length is 23 cm, the elastic potential energy of the spring is
0.18 J
b) When the stretched length doubles, the potential energy increases by a factor of four to 0.72 J
Explanation:
Hi there!
a) The elastic potential energy (EPE) is calculated using the following equation:
EPE = 1/2 · k · x²
Where:
k = spring constant.
x = stretched lenght.
Let´s calculate the elastic potential energy of the spring when it is stretched 3 cm (0.03 m).
First, let´s convert the spring constant units into N/m:
4 N/cm · 100 cm/m = 400 N/m
EPE = 1/2 · 400 N/m · (0.03 m)²
EPE = 0.18 J
When its length is 23 cm, the elastic potential energy of the spring is 0.18 J
b) Now let´s calculate the elastic potential energy when the spring is stretched 0.06 m:
EPE = 1/2 · 400 N/m · (0.06 m)²
EPE = 0.72 J
When the stretched length doubles, the potential energy increases by a factor of four to 0.72 J