Hello! There are many indicators to show a sign that a chemical reaction has occured. These are 3 as followed.
1. An odor is produced.
2. A change in temperature.
3. A color change.
Others can be a formation of a solid or a gas.
Well the US doesn't naturally have a lot of fossil fuels so we rely on other countries who do have fossil fuels. So if we aren't that friendly with Saudia Arabia (they have a bunch of oil) then they can hike up the prices or cut us off from their oil supply completely which would cripple the US severly. So with that being said, we NEED other countries, and the big question is when will they not NEED us. At any point in which they feel that they don't need us they can just cut us off, which would be bad.
Hope that helps :)
V=IR
60-V
The current that passes through a 10-ohm resistor = I
I=60/10
6 amperes
We will have the following:
![\begin{gathered} F=G\frac{m_1m_2}{r^2}\Rightarrow F=\frac{(6.67\ast10^{-11}m^3\ast kg^{-1}\ast s^{-2})(50kg)(50kg)}{(0.3m)^2} \\ \\ \Rightarrow F=1.852777778...\ast10^{-6}N\Rightarrow F\approx1.85\ast10^{-6}N \end{gathered}](https://tex.z-dn.net/?f=%5Cbegin%7Bgathered%7D%20F%3DG%5Cfrac%7Bm_1m_2%7D%7Br%5E2%7D%5CRightarrow%20F%3D%5Cfrac%7B%286.67%5Cast10%5E%7B-11%7Dm%5E3%5Cast%20kg%5E%7B-1%7D%5Cast%20s%5E%7B-2%7D%29%2850kg%29%2850kg%29%7D%7B%280.3m%29%5E2%7D%20%5C%5C%20%20%5C%5C%20%5CRightarrow%20F%3D1.852777778...%5Cast10%5E%7B-6%7DN%5CRightarrow%20F%5Capprox1.85%5Cast10%5E%7B-6%7DN%20%5Cend%7Bgathered%7D)
So, the force is approximately 1.85*10^-6 N.
Answer:
Explanation:
Far point = 17 cm . That means he can not see beyond this distance .
He wants to see at an object at 65 cm away . That means object placed at 65 has image at 17 cm by concave lens . Using lens formula
1 / v - 1 / u = 1 / f
1 / - 17 - 1 / - 65 = 1 / f
= 1 / 65 - 1 / 17
= - .0434 = 1 / f
power = - 100 / f
= - 100 x .0434
= - 4.34 D .