Answer:
b.
Explanation:
-vesign shows the lens is <em><u>C</u></em><em><u>O</u></em><em><u>N</u></em><em><u>C</u></em><em><u>A</u></em><em><u>V</u></em><em><u>E</u></em>
<em><u>f</u></em><em><u>=</u></em>1/power
A projectile fired upward from the Earth's surface will usually slow down, come momentarily to rest, and return to Earth. For a certain initial speed, however it will move upward forever, with its speed gradually decreasing to zero just as its distance from Earth approaches infinity. The initial speed for this case is called escape velocity. You can find the escape velocity v for the Earth or any other planet from which a projectile might be launched using conservation of energy. The projectile of mass m leaves the surface of the body of mass M and radius R with a kinetic energy Ki = mv²/2 and potential energy Ui = -GMm/R. When the projectile reaches infinity, it has zero potential energy and zero kinetic energy since we are seeking the minimum speed for escape. Thus Uf = 0 and Kf = 0. And from conservation of energy,
Ki + Ui = Kf + Uf
mv²/2 -GMm/R = 0
∴ v = √(2GM/R)
This is the expression for escape velocity.
Answer: The correct answer is "metalloid".
Explanation:
Metal is the material which can conduct electricity as it contains free electrons. It is good conductor of electricity. For example, copper, silver.
Metal can be drawn into wires. This property of material is called ductile.
Metal can be beaten into sheets. This property of material is called malleable.
Non metal is the material which cannot conduct electricity as it does not contain free electrons. They are poor conductor of electricity. For example, oxygen.
Metalloid: It has properties of both metals and non metal. It is electrical conductor. For example, semiconductor- silicon and germanium. But they cannot be pulled into wires.
Therefore, a material you are testing conducts electricity but cannot be pulled into wires. It is most likely a metalloid.
Silver: bonds with other atoms because of the weak forces of the valence electrons
FALSE - The strong forces of the valence electrons is actually the reason why silver bonds with other atoms.
Water: bonds allow for liquid state at room temperature and prevent conduction
FALSE - Water is a good conductor.
Carbon: bonds with other atoms through strong shared electrical bonds
TRUE - Carbon shares covalent bonds with other atoms.
Niobium: bonds allow for a strong conductivity found in stainless steel
FALSE - Iron and Carbon make up steel.
