# apurvmj

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19

1. ## Einstein's riddle

I'm so lucky to be normal by including myself in group of 98% , btw I have fish everyday.
2. ## Relation between

As per wikipedia In physics (especially astrophysics), redshift happens when light seen coming from an object that is moving away is proportionally increased in wavelength, or shifted to the red end of the spectrum. As per #Purephysics its effect of frequancy. If wavelenght of light wave increaces to maintain the speed its frequancy should decrease. But if frequacy changes so does the properties of EM waves. can we say red light will become infra red when we move away from red light source? correct me wherever I'm wrong. When will time dialation come in to play? Does it have any effect on frequancy as its time function. For me understanding Doppler effect with sound frequancies is easy, as they are pressure waves, but its difficult with "super natural kind " light waves. Hope you all understand my position.
3. ## Relation between

As speed of light is same always,will some one pls explain special relativity & red shift of light (Doppler effect).
4. ## Energy used in doing work

I guess if you are not allowing object to free fall then again you are doing positive work. like when we step down through staircase we do work and it needs energy.
5. ## Energy used in doing work

Hello everyone, lets say we have a object of mass 1 Kg kept on a table it will have energy at rest & potential energy. If I lift it to 1m up and kept it to same location back, object will have same energy. Can we say all energy is used in motion of object. Where that energy go? is it wasted/used? or converted to other form? Hope I have made myself clear.
6. ## why light takes about 8 min. to reach the earth from sun

I concluded that this all mess started due to fact that photon has momentum but no mass at rest. Strange fellow. Ya it should gain some weight, Mr. Photon pls have some healthy food. you are driving whole world crazy.
7. ## why light takes about 8 min. to reach the earth from sun

While searching for derivation for E= mc2 I come across this http://www.adamauton.com/warp/emc2.html firstly it was 'thought experiment' if this is to be believed 'm' in this equation is assumed mass of photon which supposed to be zero. and we all know that zero cant be cancelled from either sides of equation, its not valid. its like proving 1 = 2. correct me if I'm wrong, coz my small head is spinning.
8. ## why light takes about 8 min. to reach the earth from sun

I know that the because of distance between sun & earth, light takes aprox. 8 min. but its just a formula based calculation, cause we never (I guess) conducted any experiment to do that. # space stuff, I don't want to make complecated but its Einstein who is responsibbl,e I was very much happy with Newton's theory. #md65536, as far as I know object aproching speed of light its own length decreases not the path length. My one more question is when say any object (other than photon) travelling at 50% of speed of light then time frame for that object is slower by 50% but then for fixed length doesn't that object experience an ( may be psuedo) accelaration?
9. ## why light takes about 8 min. to reach the earth from sun

As stated in theory of relativity, as the speed of any object inceases its relative time decreases. Is it not applicaple to light it self. At its very own speed light's relative time should be zero and it should reach earth for that matter instantly. your view pls
10. ## pressure on gas & liquids

But I'm curious to compare that for different kind of materials, keeping some parameters same like volume & pressure, how much energy they hold. I can find it for air as pressure * volume = 106 * 1 = 1000000 J (10 kg/cm2 = 106 N/m2) But how can I find the energy hold by water of 1 m3 at 10 kg/cm2 .
11. ## pressure on gas & liquids

correct me if I'm wrong for my 'example' part, I got one formula for gases energy= pressure*volume. Is same applicable for liquids? I'm keen to know that does water & air of same volume & same pressure hold the same energy?
12. ## pressure on gas & liquids

Hi all, It is said that liquids are mostly non compressible & gases are compressible. Could some one pls explain, do both require same energy to have same pressure? For example how much energy it requires to compress air of 1 m3 to 10 kg/cm2 & water of 1 m3 to same10 kg/cm2 Thanks.
13. ## Current flow direction in circuit

How can we explain +ve charge in AC or DC generator? Coz in magnetic field only electron that moves. Also in lightening strike, as heavily -vely charged clouds discharges to neutral ground. Ground is not +vely charged I guess. Pls correct me if I'm wrong.
14. ## Current flow direction in circuit

Hi all, I'm having a small question about current flow direction indication in circuit diagrams. Its shown as current flow from +ve pole to -ve pole, but -ve pole has higher electron concentration (potential) & electrons flow from -ve to +ve. Whats the logic of showing the direction of current flowing in opposite way. Hope I have made myself clear. Waiting for reply. Thanks.
15. ## The Official "Introduce Yourself" Thread

Myself Apurv (male) from Mumbai, India an civil engineer by profession. I'm a knowledge seeker & athiest by belief. I love trekking, watching animated, comedy & science fiction movies. Thats me in short
16. ## Solar powered space craft

pls correct me if I'm wrong but my point was related to whether light has mass or not? Btw I did post my same post again in that topic by mistake, pls excuse me.
17. ## water air composite pressure system

Hi all, I,m plannig to conduct one experiment, but before that I wanted it confirm whether my idea has got some scence. My query is lets consider we have 3 types of system 1.Closed air tank at 10 bar pressure. It will have pressure* volume = 10*105*1= 1000 KJ energy. 2. Water tank of volume 1 cum and height of water 1 m. It will have 5.04*h2 = 5.04 KJ (h= water head pressure) 3. Now lets say we have 2 cum of closed volume containing water of 1 cum and 1 cum air at 10 bar. can I say we have energy in water= 5.01*1002 = 50400 KJ (10 bar=100 m of water) plus when water is out of tank volume of air will be 2 cum at 5 bar. then energy stored in air (considering isothermal expansion)= 500 KJ so total 50900 KJ. Am I doing wrong some where/ everywhere then where is it wrong? If not why there is so diffrence in energy?
18. ## Solar powered space craft

hey guys have you heard/seen about intergalactic space craft propelled by light hitting umbrella like structure of space craft, giving very little push to space craft. And idea is over a long distance it will have speed equal to some % speed of light. cause I have seen this in discovery channel. How can we explain this?
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