Answer:
Hydrogen and helium compounds.
Explanation:
We know that the solar System was formed around <u>4.6 billion years ago, </u>due to the gravitational collapse of a giant interstellar molecular cloud.
This cloud is a type of interstellar cloud and its density and size permit the formation of molecules, most commonly molecular hydrogen.
Therefore the principal substances were found before planets began to form are hydrogen and helium compounds, besides Rocks, metals, most of them in gaseous form.
I hope it helps you!
C. Thick wire and cold temperature.
Explanation:
The resistance of a wire is given by: R = (ρL)/A
where ρ is the resistivity of the material, L is the length of the wire, A is the cross-sectional area of the wire.
From the formula, we see that the thicker the wire, the larger A, therefore the smaller the resistivity. so, a thick wire will have lower resistivity.
Moreover, the resistance of a wire increases with the temperature. In fact, high temperatures mean more motion of the atoms/electrons inside the wire, so more resistance to the flow of current through it. Therefore, colder temperature means lower resistance.
So, the correct option is thick wire and cold temperature.
Answer:
A charge of -5.02 nC is uniformly distributed on a thin square sheet of nonconducting material of edge length 21.8 cm. "What is the surface charge density of the sheet"?
Explanation:
Surface charge density is a measure of how much electric charge is accumulated over a surface. It can be calculated as the charge per unit area.
We will convert all parameters in SI units.
Charge = Q = -5.02nC
Q = -5.02×
C
As it is clear from question that Sheet is a square (All sides will be of equal length)
Area = A = (21.8×
m) (21.8×m) = 4.75×
m²
A = 4.75×m²
Surface charge density = Q/A
Surface charge density = (-5.02×C)/(4.75×m²)
Surface charge density = -1.057×
C
☁️ Answer ☁️
annyeonghaseyo!
Your answer is:
True.
Several simple machines change the direction of the applied force. These include lever, fulcrum and the pulley.
Hope it helps.
Have a nice day hyung/noona!~ ￣▽￣❤️
