An Active solar energy system because it uses the sun to heat up the green house an I’m return the plants grow an produce food
Answer: D
Explanation: The chemical bonds in the food store energy that is released when we eat it.
Answer:
As the planets are very small and dark in comparison with stars, it makes them very hard to be found from earth.
Explanation:
Astronomy, of course, has a solution for this. As astronomers can't observe planets directly, they decided to observe the stars and search for the effects that planets have on them.
There are many ways of observing the exoplanets: Radial Velocity, Transit Photometry, Microlensing, Astrometry, Direct Imaging, etc.
Before all of this, scientist had to find ways to prove their theories. Most of their time they have spent in giving the creative answers.
Science and creativity are very much connected when we speak about the development of science. Rationality and creativity always go together.
In order to create an idea that other people will consider useful, it is important to use creativity. As no one has the exact answer when it comes to science, the adventure is to research the unknown.
Answer:
Magnitude and direction.
Explanation:
Velocity can be defined as the rate of change in displacement (distance) with time. Velocity is a vector quantity and as such it has both magnitude and direction.
Mathematically, velocity is given by the equation;

Gravity is considered to be a universal force of attraction which acts between all objects that has both mass, energy and occupy space. Therefore, it acts in such a way as to bring objects together.
Additionally, the gravity of earth makes it possible for all physical objects to possess weight.
Hence, in free fall, the magnitude and direction of velocity of the object changes.
Answer:
Simple machine
Explanation:
It is a simple machine because the person wants to raise the load by an inclined plane. Simple machines perform work with the mechanical advantage offered by the machine itself, such as using a bar as Lever, lifting a load by means of a pulley. simple machines multiply or change direction a force. While Composite machines are the Union of several simple machines that perform a given job, examples of combined machines are found on bicycles, a washing machine, a car, and others.