I think the answer is D
Hope this helps :D
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.
Primary Waves
Secondary go only through air, but not water.
ANSWER:
250 J
STEP-BY-STEP EXPLANATION:
F = 20N is required to stretch the spring by 4 meters
We know that the force is equal to:
We solve for k (spring constant):
The work done in stretching the spring is given by the following equation (in this case the stretch is 10 meters:
The work required is 250 joules.
