Solar radiation is incident on a planet, whose surface absorbs 65% of inciden-:sj *vwonyotd 11sq zoo/;c6 t intensity. What -6 zdcj1tsw; oo/vq sy o:1no*is the albedo of the planet?

  The orders of energy tr(s5d xsivh zgcft29-* ajrs15ansformations in three power 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 constitutes a renewable and non-renewable scw3od :x et/-a*rf8y*c r2u ooource of energxc:yf od or 2*/o *uwa-8ectr3y?

  Which of the following1::n38 t z+jxocklq 6vq pxr0m pairs constitutes a renewable and non-renewable source of energt8vj 6 x + :c30x:zrmnolpq1qky?

  Which of the following is a non-renewable energy resomo 6m pfu:(n(wgvmt** urce?

  Which of the following energy r 6c0k tuguu6e2t9wio xla ;2z0esources is non-renewable?

  The government of a medium sized city plans to replace / ug,y csux:r.coal power plants with photovoltaic cells to power the cityu,g .:xy/s rcu.
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 ep(e8r eu xc61the Sun is approximately 30 times the orbital radius of earth. Estimate the solar constant eux1reep( c86 of Neptune.

  The following three statements db8r8xrytm08v7vrk l qx:v08give possible reasons why the average intensity of sunlight incident on a solar panel during a day on ear08 ryr 8kbml8 8tq0vxd 7rvxv:th 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 occur in power stations. Examples oie3pldp;f) y ma8e: .rf electricity generation that both involve energy transfer from thermal to elf pyareeim;8:.dl 3p) ectrical are

  The albedo at the poles of 0i4y)c;1 ix s, wdyrmfyy;r8zEarth during a particular day is 0.8. What is the value of the absorbed intensity if the solar);smxy,y icyi 4y 0;1rrz8 fdw intensity is 700 $Wm^{−2}$?

  The sun radiates energ u.fwo*v3g2+zs-g rrhf.3mu zy to the surface of the earth. Some of this energy is scat*rw+ . zfruz vfg sm3u.g2o3h-tered 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 solna7 2ye0fe o(cru4iq9ar 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 7;u b2pze *kzr 8zhwd2with a specific 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 albedo ofq*x p*qmv)hef9kh3 t 0 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.