Solar radiation is incident on a planet, whvg/i9d kd s-z(zt. h0;jb5hhl p/y9v fose surface absorbs 65% of incident intensity. What ihv.b;z-dv/g5k9l0 hftih sd9 pj( /yz s the albedo of the planet?

  The orders of energy transformations in three powerxyn0x cs64x1+r5dbhsl23i wr 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 pairs8pg*4mr ht2 pg constitutes a renewable and non-renewable source of energrgtpmph2g* 4 8y?

  Which of the following pairs constitutes a renewable.ow.+cgu/5;woxg iku .,pgpn and non-renewable source of energ+i5cw.o/w px,u kguo gg.;pn.y?

  Which of the following is a non-renewable energy fu* t1 m6jxj:iresource?

  Which of the following energy resources is non-renewabuh ijyoeaoj7(-,4b9b7hzv f* le?

  The government of a medium sized city plans to replace coal power plants with p 8wrb owhn00x4hotovoltaic cells to pwr480w0hxbn oower 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 theni:bi /we3ix. Sun is approximately 30 times the orbital radius of earth. Estimate the solar constaexi:iwb.n 3/ int of Neptune.

  The following three statements give possible reasons 9+r3wakm 4vnysgqu,-zq*is 3why the average intensity of sunlight incident on a sol3gz4rv,qa -isu+qs9*3ym wk n ar 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 conversionseg-sdq . ky9q7 occur in power stations. Examples of electricity generation th7y-k.sd ge qq9at both involve energy transfer from thermal to electrical are

  The albedo at the poles of Ea, b t0dekhh 3kclff+t73vsf 7gm*ow40rth during a particular day is 0.8. What is the value of the absorbed intensity if the solar inktfbv 7t3 soh+d 4m* 3e00lwg 7ffchk,tensity is 700 $Wm^{−2}$?

  The sun radiates energy to the surface of 4 fwjl+;1,qtzdhx s 0othe earth. Some of this energy is scattered and tdjzwo 0+xsf,l 1q 4ht;he 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 solar intensity on the Eartac n xwsx3c*3/upnq3-h'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 speclpioa0t)y6oqzbkc6 5/0 9z u mific 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 bodk 4gzbm6:- j46mr zdpmd 9qha(vp(z6qy
(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.