"A machine can decrease either the input force or the input distance needed to do a given amount of work" is the best statement that describes why a machine is useful.
Answer: Option D
<u>Explanation
:</u>
A machine is simply defined as a device that helps humans, helping them to transfer the required amount of force to compete any task, changing the direction of motion, increasing the magnitude of force to complete any task, reduce the time or distance needed to cover while performing any task.
Machines can be simple mechanical device or a combination of multiple mechanical or technical devices to reduce the amount of input force or increase the output.
Oxygen had 6 valence electrons
Answer:
Pure solid and liquid compounds possess sharp melting and boiling points.
Explanation:
Therefore, melting and boiling points of a compound can be used as a criteria of purity. ... Sometimes during cooling minute quantity of the substance (solid which is being purified) is added to the solution to facilitate the initial crystallisation.
Answer:
The correct answer is number 2. Elliptical, Spiral, Irregular.
Explanation:
Unfortunately, you did not attach the passage. Without the passage, we do not know what its content is.
So we are going to answer this question with our own knowledge.
The types of galaxies by their ability to form new stars, from most to least activity are "Elliptical, Spiral, Irregular."
That is the way astronomers classify galaxies in scientific terms. These scientists consider that the smallest galaxies or dwarf galaxies have approximately 100 million stars. On the other hand, giant galaxies have billions or trillions of stars. That immense is our universe.
Scientists still studying the universe and the galaxies to understand the way galaxies are formed.
It's -Bohr's Model- becuase Dalton I dont think did a model. Thomson's was the "Plum Pudding Model." Ernest Rutherford drew one out(I dont know i dont have a model down though) so it the only one left is Dalton's Model which is it. (Hopefuly)