Solar radiation is incident on a planet, whose sqwse i-.ahvm( l4 /i;mx gq8k/urface absorbs 65% of incident intensity. What is the albedh/ml-wa.;v/4eq8g qk sxi im(o of the planet?

  The orders of energy transformations in three powe 3+jj yzgi-0blr 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 following8:f2+-il h 5ybghebut pairs constitutes a renewable and non-renewable source of energth 2f:eu+blih-5 ygb 8y?

  Which of the following pairs cly6 wxoy1,/ aronstitutes a renewable and non-renewable source of enyyx6a r1wo/, lergy?

  Which of the followigej21eue:o dda53 j:b ng is a non-renewable energy resource?

  Which of the following energy resources is non-ryi/i 4xtwbmm aic ,/*(enewable?

  The government of a medium sized city plans to replace coal powerk1 cfqunqzzi 4// w7e8 plants with photovoltaic cells to po8z c1f/uzi /wn4q7eq kwer 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 approx o fw w( *mrwjk/3n(*2nxw2oanimately 30 times the orbital radius of earth. Estimate the solar constant omnr fk/2(**3wnn2wo(owj wax f Neptune.

  The following three statements give possible reasons why tl+2hy.i;ubpg8favq 7g 5 eqv.he average intensity of sunlight incident on a solar panel during a day on earth is only a fractie.v78g p+vgba5lf. qyq hu ;2ion 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 conversio uj4(( x +tw7/codlzjxns occur in power stations. Examples of electricity generation that both involve energy transfer from thermal zxjl wdj7 (+t(4uc x/oto electrical are

  The albedo at the poles of Earth during ch*2fg6/ znsdw uk;9zi5 ihy7a particular day is 0.8. What is the value of the absorb6hnd7zifyu9ch izgk2 s/;*5wed intensity if the solar intensity is 700 $Wm^{−2}$?

  The sun radiates energy to the subw jx0m u7 ytxzh8 5q8 y5mpsoqt,:4n/rface of the earth. Some of this energy is scattered and the rest reaches the earth's surface.w 4/5ysp7xq x5, otbyuh80mn8j:m qtz



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 soy vevqz v7pywf ,jvx,7lqcm ((7d)k2*lar 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 st*i3n:g(qk5 jbb+s4hp z p9*4a pyfkapecific 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 of a body ffqqh 0qoi-a l0t* ajt)a)-1t
(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.