Solar radiation is incident on a planet, whose sp9xp,nn a49scxe 7uwc: l eb/7urface absorbs 65% of incident intensity. What 9ce: x p9ecl7bsan74xp /nuw, is the albedo of the planet?

  The orders of energy transformations in three 6zn 7s.g3y gp 72lp8nquj(b fqpower stations are given;

I. chemical → thermal → kinetic → electrical
II. kinetic → kinetic → electrical
III. gravitational potential → kinetic → electrical
Which row correctly matches the type of power station with the energy transformations?

  Which of the following pairs constfx/9;* mwq. h-k acgdyitutes a renewable and non-renewable source of energ acdqygm.*k/x9h -wf;y?

  Which of the following pairs constitutes a reny+zyi6i q()2ytth 8 msewable and non-renewable source of ehi(8 q )ttyzs y+m26yinergy?

  Which of the following is a non-renewable energy reso/eax9 uvj7blve ,w, qal9s0;u urce?

  Which of the followit3+x9nipemx h :,gjs, ng energy resources is non-renewable?

  The government of a mediu 8pil:bc3h +o kf*b(aqm sized city plans to replace coal power plants with photovoltaic cells to pac*lb8i3:( + bfqhkpo ower the city.
The following data are available:
Total area available for photovoltaic cells = 62.6$km^2$
Maximum intensity of light incident on photovoltaic cells = $1.36\times10^3$ $Wm^{−2}$
Average efficiency of energy conversion in photovoltaic cells = 20 %
Hours of sunshine in one month = 150 hours
1.Explain why the government's choice to reduce its reliance on coal would be beneficial to the Earth's climate.
2.Outline, in terms of energy changes, how electrical energy is generated from coal.
3.Using the data given, calculate in $GJ$ the maximum expected energy generation for one month. $Electrical energy obtained$ =    $\times10^6\,GJ$

  The average radius of Neptune's orbit around the Sun is approximately 30 timetu55;b9wlun+ k x f3:t+ sovkbs t+xsf5 :5u nbv3kb t;owk9tlu+ he orbital radius of earth. Estimate the solar constant of Neptune.

  The following three statements give possible reasons why thdioy+ 9bhr)llwh3jv cc .-e0jppc -,+e average intensity of sunlight incident on ahcc+vcdw30,--j lb9h. yeijl )p r+po solar panel during a day on earth is only a fraction of the solar constant.
I. Scattering of sunlight in the atmosphere
II. Rotation of the earth
III. The surface of the solar panel is not perpendicular to incident of sunlight
Which of the statements are correct?

  Several energy conversions oam:k :ba ukq02ccur in power stations. Examples of electricity generation that both involve energy transfer from k::0a2muaqbk thermal to electrical are

  The albedo at the poles of Earth dujiiu*sx e*j y ;v5bph8xo;3b+ring a particular day is 0.8. What is the value of the absorbed intensity if the solar int8y *suh5bxjbv e*3;;p ox iij+ensity is 700 $Wm^{−2}$?

  The sun radiates energy to the surface of the earth. Some f:l di :22 x 5n*ufj28ic9ozm v-fwoscof this energy is scattered and the rest reaches 859cj2 mln- :f*2iux2 isv:ozwcffdothe earth's surface.



1.Differentiate between heat transfer methods: conduction, convection and thermal radiation.
2.At any given time, the power of the radiation of the sun absorbed by the earth's surface is $P$.
$P$is given by
$P\,=\,(1−α)SπR^2$
Where $α$ is the albedo of the earth’s surface.
(1)Show that the average intensity of radiation $I_{avg}$​ that is absorbed by the earth's surface is given by $I_{avg}$​=$\frac{(1−α)S}{4}$. ​
(2)Calculate the average intensity of the radiation that is absorbed by the earth's surface. The earth's albedo is 0.3. $I_{avg}$ =    $Wm^{-2}$
Some of the infrared radiation from the earth is absorbed and reradiated by the greenhouse gasses.
3.Explain this absorption and emission of radiation in terms of molecular energy levels.

  On a certain day, the solar inten 4d:jo5yzw9 xfsity on the Earth's surface is 300 $Wm^{−2}$. Photovoltaic cells which have an efficiency of 20% are used to convert solar energy to electrical energy. What should be the minimum area of the photovoltaic cells to produce an output of 6.0 kW assuming that the incident light is normal to the surface of the panel?

  A natural gas plant burns fuel with a specificb(g) ;yw xcgv: energy of 80$MJkg^{−1}$.
The rate of energy input of the natural gas is 1.6$GW$. What is the rate at which the fuel burns?

  1.(1)Define the albedou cb6rv//kapt4ti 6a9 of a body
(2)It was suggested that painting rocky mountain tops with a white chalk-based paint could help reduce the impact of global warming. In terms of albedo, explain why this could work.
2.(1)Given that the radius of the earth is $6.4\times10^6\,m$, show that at any given time, the total amount of energy incident on the earth's surface is approximately $1.8\times10^{17}\,J$ per second. P =    $\times10^{17}\,W$
(2)The average albedo of the Earth is 0.30. What is the rate at which the Earth absorbs energy from the sun?
(3)Using your answer from (b)(ii) and ignoring atmospheric effects, estimate the average temperature of the earth for which equilibrium would be established. Assume the earth's average emissivity is 0.80.T =    K
(4)Greenhouse gases in the atmosphere elevate the average temperature of the earth such that it is higher than the answer found in (b)(iii). Explain the mechanism by which this occurs.