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:
Force = 150 Newton.
Explanation:
Given the following data;
Mass = 60kg
Acceleration = 2.5m/s²
To find the force;
Force = mass * acceleration
Force = 60 * 2.5
Force = 150 Newton.
Therefore, the force required to accelerate this mass is 150 Newton.
Answer:
More than enough solar energy (8.2 million quad BTUs, 1 quad = 2.9 x1011 kWh) hits Earth's surface each year to meet all of societies' needs. Currently we use about 400 quads per year to run our society. Good building design allows passive use of sunlight to heat homes. Simple solar collectors are used to heat water and cook food. As useful as it is for these purposes, thermal energy from sunlight is still a low quality energy compared to electricity. Computers, most machinery, light bulbs, subway trains, and much more all require electricity. It is possible to turn thermal energy from the sun into electricity. In this unit we will examine how.
. We will also examine how to make electricity directly from light using the photovoltaic cells.
