<h2>Answer: free electrons</h2>
<u>Plasma</u> is known as the 4th state of matter and is itself ionized gas. In this sense, ionization consists of the production of ions, which are <u>electrically charged atoms or molecules due to</u><u> the excess or lack of electrons</u><u> with respect to a neutral atom or molecule.
</u>
That is why in this process there are always<u> free electrons</u>. Therefore in heating gas to create plasma can yield free electrons, and the correct option is D.
D. they are composed of two or more types of matter
Answer:
3.085 [m].
Explanation:
1) The rule:
m₁*g*l₁=m₂*g*l₂, where m₁ and l₁ - the mass and distance for the small child, m₂ and l₂ - for the big child;
2) according to the condigion l₁+l₂=5, then
3) it is possible to make up the system:
![\left \{ {{l_1+l_2=5} \atop {m_1*l_1=m_2*l_2}} \right. \ = > \ \left \{ {{l_1=5-l_2} \atop {18*(5-l_2)=29*l_2}} \right. \ = > \ \left \{ {{l_1=\frac{145}{47}} \atop {l_2=\frac{90}{47}}} \right.](https://tex.z-dn.net/?f=%5Cleft%20%5C%7B%20%7B%7Bl_1%2Bl_2%3D5%7D%20%5Catop%20%7Bm_1%2Al_1%3Dm_2%2Al_2%7D%7D%20%5Cright.%20%5C%20%3D%20%3E%20%5C%20%5Cleft%20%5C%7B%20%7B%7Bl_1%3D5-l_2%7D%20%5Catop%20%7B18%2A%285-l_2%29%3D29%2Al_2%7D%7D%20%5Cright.%20%5C%20%3D%20%3E%20%5C%20%5Cleft%20%5C%7B%20%7B%7Bl_1%3D%5Cfrac%7B145%7D%7B47%7D%7D%20%5Catop%20%7Bl_2%3D%5Cfrac%7B90%7D%7B47%7D%7D%7D%20%5Cright.)
4) finally, l₁=145/47≈3.085 [m].
(2)<span>less than 750 N.( if the downward acceleration of elevator were g,then answer would be 0 N.)</span>