Solar radiation is incident on a planet, whose surface absorbs 65% of ./mefmr:8vd(oo ax3 g (eyv3tincident intensity. What is the al vyd/8.mv(gr3 ome o:xt3( efabedo of the planet?

  The orders of energy transformations in three power staa h8hln+ -6mb.4hua otkue)l- tions 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 pairnmz 6wu:*xtw9er r3- fs constitutes a renewable and non-renewable source of rf3wztw-ex*:r um n96energy?

  Which of the following pairs consd )c4lpdt6o ;s g4e5nl46geljpim5 g:titutes a renewable and non-renewable source of energyd;njic lgod4 )egp4slm6eg5:6p tl54?

  Which of the followin3k- 4mqzt4lo ag is a non-renewable energy resource?

  Which of the following energy resources is non-reneiyr 1qim df7,.org vg4n /1gj.wable?

  The government of a medium sized city plans to replac b+pa7jmq;zt4g h*6 /xr usr;9*fgznce coal power plants with photovoltaic ce*9z6smh*p/b n7fa;turc;g z qjxg4 + rlls to power 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 ap qcrlr7pzd(j/ la2h0,proximately 30 times the orbital radius of earth. Estimate the solar constant of Ne7zrq/(,djh p a0r2cllptune.

  The following three statements give pky96 k .1k7c+ e o:,dy qo3pvtwpyy/sz.do6ksossible reasons why the average intensity of sunlight incident on k9 ody+c, oyet w y6s.1qp p73k.yk:k/v d6szoa 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 converv3,;mnqn1vs ww)/f f psions occur in power stations. Examples of electricity generation that both involve energy transfer from thermal tof3 qfw)vs;wv1m ,nnp / electrical are

  The albedo at the poles of Earth during a particular day is 0.8. What is the-l ;.b48mb,as temi7 l/jm tfe value of the absorbed intensity if the solar intensity is b;t atm 78je4smlil./-bf ,me 700 $Wm^{−2}$?

  The sun radiates energy to mi5(i io6j k0ithe surface of the earth. Some of this energy is scattered(i5ii jk6i0om and the rest reaches the 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 sola8nk4 g 71r6sw/db;hup +ojbhcr intensity 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 specific energy of 47e4xep : amzo80$MJkg^{−1}$.
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 albedo beled+sd)*4r*xb.a pl ue,9n6 a ynd)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.