Guest Posted February 22, 2011 Report Share Posted February 22, 2011 (edited) My botany sir asked us this question: You know, plants absorb 2% of sunlight. Why do you think they do this (i.e; absorb 2% of sunlight)? The answer left us speechless. Honestly its not a great riddle, but I felt like posting it Lets see if you can think like my professor Edited February 22, 2011 by sana88 Quote Link to comment Share on other sites More sharing options...
0 Guest Posted February 22, 2011 Report Share Posted February 22, 2011 It has to do with the light spectrum and the fact that chlorophyll doesn't absorb all of the wavelengths of light equally. Quote Link to comment Share on other sites More sharing options...
0 Guest Posted February 22, 2011 Report Share Posted February 22, 2011 Land covers 30% of earth's surface. 46% of that is cover by plants. Given that only half of the earth faces the sun, while the other half is in darkness, this leaves approximately 7.5% of area that is plants(on land) and faces the sun to absorb sunlight. However there is a much larger volume of marine algae that absorbs a lot more sunlight that what the plants on surface absorb so my value of 7.5% is way out of the real value. In addition they also reflect light(which is what makes any object visible). Only selected wavelengths are absorbed by plants and at a different percentage. I would like to know what the answer of your teacher was Quote Link to comment Share on other sites More sharing options...
0 Guest Posted February 22, 2011 Report Share Posted February 22, 2011 Land covers 30% of earth's surface. 46% of that is cover by plants. Given that only half of the earth faces the sun, while the other half is in darkness, this leaves approximately 7.5% of area that is plants(on land) and faces the sun to absorb sunlight. However there is a much larger volume of marine algae that absorbs a lot more sunlight that what the plants on surface absorb so my value of 7.5% is way out of the real value. In addition they also reflect light(which is what makes any object visible). Only selected wavelengths are absorbed by plants and at a different percentage. I would like to know what the answer of your teacher was um...no! i loved my teacher's answer! but sorry, this is not the answer iam lookin for keep trying though Quote Link to comment Share on other sites More sharing options...
0 Guest Posted February 22, 2011 Report Share Posted February 22, 2011 (edited) It has to do with the light spectrum and the fact that chlorophyll doesn't absorb all of the wavelengths of light equally. sorry, no, that's not the answer keep trying though! Edited February 22, 2011 by sana88 Quote Link to comment Share on other sites More sharing options...
0 Guest Posted February 22, 2011 Report Share Posted February 22, 2011 no surface is perfect reflector Quote Link to comment Share on other sites More sharing options...
0 Guest Posted February 22, 2011 Report Share Posted February 22, 2011 (edited) Plants absorb light through their leaves, principaly in the red and blue spectrum. Certainly not light in the same colour spectrum as their leaves. Also for plants to absorb light for photosynthesis there must be carbondioxide and water. Taking all these factors, you have the 2% ??????? Edited February 22, 2011 by davight Quote Link to comment Share on other sites More sharing options...
0 Guest Posted February 22, 2011 Report Share Posted February 22, 2011 Because it reflects 98% Quote Link to comment Share on other sites More sharing options...
0 Smith Posted February 22, 2011 Report Share Posted February 22, 2011 they cover 2% of the earth's surface? The question is a little vague to my mind. Is it that they absorb 2% of the sunlight that reaches the earth, or that they absorb 2% of the sunlight that hits them? Quote Link to comment Share on other sites More sharing options...
0 Guest Posted February 22, 2011 Report Share Posted February 22, 2011 Because if they absorbed 100% of sunlight, they would be black. Quote Link to comment Share on other sites More sharing options...
0 Guest Posted February 22, 2011 Report Share Posted February 22, 2011 Because it requires only that much .2ndly every plant absorbs sunlight to produce their own food! Quote Link to comment Share on other sites More sharing options...
0 Akriti Posted February 22, 2011 Report Share Posted February 22, 2011 because they need it? Quote Link to comment Share on other sites More sharing options...
0 Guest Posted February 22, 2011 Report Share Posted February 22, 2011 The sun radiates light in all directions, only 2% falls on the earth? Quote Link to comment Share on other sites More sharing options...
0 Guest Posted February 22, 2011 Report Share Posted February 22, 2011 The sun radiates light in all directions, only 2% falls on the earth? hey!gresleysteve first I also thought the same thing but later I realized that the whole earth is not covered with plants our thoughts intersects! Quote Link to comment Share on other sites More sharing options...
0 k-man Posted February 22, 2011 Report Share Posted February 22, 2011 The sun radiates light in all directions, only 2% falls on the earth? If 2% of sunlight produced by the Sun fell on Earth the Earth would be nothing but a hot burning desert. No, I take that back, it would be an inferno. Only approximately 0.000000724654% of sunlight reaches the Earth and I don't believe the question is related to the amount of sunlight reaching the Earth. It's that the 2% of sunlight that hits the plants is absorbed by them, while 98% of it is reflected. Quote Link to comment Share on other sites More sharing options...
0 fabpig Posted February 22, 2011 Report Share Posted February 22, 2011 I think it might be "because they can". A bit like why does a dog Quote Link to comment Share on other sites More sharing options...
0 Guest Posted February 22, 2011 Report Share Posted February 22, 2011 Because it reflects 98%. Simple Quote Link to comment Share on other sites More sharing options...
0 Guest Posted February 23, 2011 Report Share Posted February 23, 2011 Because it reflects 98% hey thats the right answer! its coz the plants reflect 98% of the sunlight! trust me, even we were stunned by his answer! pretty simple and straight forward Quote Link to comment Share on other sites More sharing options...
0 Guest Posted February 23, 2011 Report Share Posted February 23, 2011 Because it reflects 98%. Simple yup,thats the right answer! its coz the plants reflect 98% of the sunlight! trust me, even we were stunned by his answer! pretty simple and straight forward Quote Link to comment Share on other sites More sharing options...
0 Guest Posted February 23, 2011 Report Share Posted February 23, 2011 I think it might be "because they can". A bit like why does a dog ha ha ha loved your answer but no, thats not it! Quote Link to comment Share on other sites More sharing options...
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Guest
My botany sir asked us this question:
You know, plants absorb 2% of sunlight. Why do you think they do this (i.e; absorb 2% of sunlight)?
The answer left us speechless.
Honestly its not a great riddle, but I felt like posting it
Lets see if you can think like my professor
Edited by sana88Link to comment
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