Solar radiation is incident on a planet, whose surface absorbs 65%tfjr6e 421g4; ior ysm of incident intensity. What is the albedo of the po2ri j;6sf1tmyg 44erlanet?

  The orders of energy transformations in three p-axj-vsy:d1ar 9b) paower 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 pa v;njc -yqo.og-fp(b, (,cj nwirs constitutes a renewable and non-renewable source of enc cojg-,-yob.n(fjq ;v, (npwergy?

  Which of the following pairs constitut,*s5wpcnl 9 vx34l mlges a renewable and non-renewable source of enern ,*4spl9cx3gm5wlvl gy?

  Which of the following is a non-renewable energy resourceca+ 32ui*qu q yzo1q0-h3xphm?

  Which of the following energy resources is non-ren 0y1kqg+n/vn,i t +fjbewable?

  The government of a medium sized city plans tod y wy-ftw,)kvjn*vt; go u/;8 replace coal power plants with photovoltaicw-ud/8 jyy vtwt; vog;f*k,) n cells 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 approximately 30 timesuc :q+t yhsgo1:- ul1v the orbital radius of earth. Estimate the solar constant of Neptunq1l: 1v+touc-y gush:e.

  The following three statements give possible reasons why th1n jc bans 8b8q k6f,1al.kp(te average intensity of sunlight incident on a solar panel during a day on earth is only a fraction of t8a knckptf ba 11s,bnq(l8.6j he 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 of electricity7 rzmqz-,vqv(3wy , ns generation that both involve energy tranmy nzzw,37(r-,v qs qvsfer from thermal to electrical are

  The albedo at the poles of Earth during fd 9l:, qw6nioc4em4o a particular day is 0.8. What is the value of the abneq4o,l foi c69:4mwd sorbed intensity if the solar intensity is 700 $Wm^{−2}$?

  The sun radiates ener:d3 qvvzk:01u*//q qpha ugkmgy to the surface of the earth. Some of this energy is scattered and a1khqk:v * q vguq3d: u0/z/mpthe 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 Eaej llx8y- 1c0 f*w0-i fs:catab ne+rc.gx2q;rth'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 withb .(q gaoekx u3:7v:h4jqag/nzsk /(o 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 of,ppguud b1g9-1uj d9vy 4zd8 w 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.