Answer:
7.99 or 8 depends where you round.
Explanation:
Distance divided by time so 1246/156=7.98717948718
It would be "Researchers found environmental safe replacements for CFC's"
- Demand of natural resources have influenced human settlement plans .
- Clean air,clean water and food are examples of natural resources
How demands became the obstacles ?
- The demands forces the human to go to different places in order to fulfill their requirements .
- So they have to shift their homes to different places .
It be desirable to use an energy resource that does not produce greenhouse gases because it contribute to climate change
.
Option C
<u>Explanation:</u>
Greenhouse gases are the toxic gases that contribute to the "greenhouse effect". Greenhouse gases have the ability to absorb and emit some of the outgoing energy that is radiated by the Earth's surface, eventually causing the heat to get accumulated in the "lower atmosphere". It is always beneficial to use Renewable Energy sources such as Wind, solar and water which gives no harm to the environment and climate with no greenhouse gas emissions.
<u>For example:</u> If we have to generate electricity, there will be no greenhouse gas production at the beginning and a very less amount of production at the entire life cycle.
From the concept of optics on a curvature of a spherical mirror, the proportion for which the focal length is equivalent to half the radius of curvature is fulfilled. Mathematically this is
Here,
f = Focal Length
R = Radius
Rearranging to find the radius we have,
Replacing with our values,
R = 2(13.8cm)
R = 27.6cm
Therefore the radius of the spherical surface from which the mirror was made is 27.6cm
