Physics p22

[hassam]

@gatechatl........if u hav got senses....which i dont think u hav....a samller drop will hav a smaller mass....ryt...?...so is it so hard to conceptualize....and u tell me wat assumption i made

 

[hassam]

well...guyx did they ask path difference or phase difference?

 

[Ismail Breiwish]

@gatechatl........if u hav got senses....which i dont think u hav....a samller drop will hav a smaller mass....ryt...?...so is it so hard to conceptualize....and u tell me wat assumption i made

He "hav got senses". It was never mentioned in the paper that the mass of the raindrop decreases, hence you shouldn't assume so. Yes, the volume has decreased, but you have seen in the past papers, that water could have different densities, eg water vapour @ 1/1600 kgm^-3 and water @ 1000kgm^-3. This means that the mean separation between the molecules has decreased, but the mass has not decreased. Have you actually payed attention to the past papers you have done?

 

[akbararshad]

well radius was decreased so automatically d drag force reduced...... and acceleration increases..... wats here to fight abt guys??

 

[hassam]

k i apologize for that..bt...who told u that two raindrops cn hav different densities...this is ur own assumption then...density only change when temp...is changing or state is changing,..u cnt get two drops with different density...and cud u plx post a link for the question in past papers u refrring to

 

[Ismail Breiwish]

well radius was decreased so automatically d drag force reduced...... and acceleration increases..... wats here to fight abt guys??

Thank YOU. Someone who speaks sense. BTW there's no arguing here, just an aggressive debate :wink:

 

[hassam]

well radius was decreased so automatically d drag force reduced...... and acceleration increases..... wats here to fight abt guys??

well akbar....was ur terminal velocity lower for the sketch graph....

 

[Ismail Breiwish]

k i apologize for that..bt...who told u that two raindrops cn hav different densities...this is ur own assumption then...density only change when temp...is changing or state is changing,..u cnt get two drops with different density...and cud u plx post a link for the question in past papers u refrring to

I have not assumed that they have, but you were saying that it is impossible for mass to be the same. I used to information they gave, that the formula for resistive force is what it was. I am just explaining how it COULD be possible that densities were different. While doing the question, I only used the information they gave.

 

[Ismail Breiwish]

well radius was decreased so automatically d drag force reduced...... and acceleration increases..... wats here to fight abt guys??

well akbar....was ur terminal velocity lower for the sketch graph....

Your making sense, but not in the context of this question. Good luck for any other exams you sit.

 

[hassam]

well leav it ....just tell me was question asking phase differrence or path difference?

 

[ahsan99]

Well both of your are working on assumptions. It said radius decreased
so surface area of the rain drop decreased too. Lesser resistance.
hence greater terminal velocity and more time taken to reach terminal velocity.
Simple. Both are in similar states hence density must be the same. hence mass of the second raindrop
should be more. Again whenever the mass is greater terminal velocity is more
since resultant downard force is more
Hope that clears

 

[Hateexams93]

AM I THE ONLY ONE WHO GOT 2.6 FOR THE CURRENT ?

 

[hassam]

how mass for second drop cn be more ahsan..u are contradicting urself....if radius has decreased....vol..will decrease so m=dv will DECREASE....

 

[hassam]

CNT WE HAVE CHAT ON XPF chat...COS this way its boring..i m waiting waitn....and 10 min later one reply comes

 

[BILALrox01]

guys...wat was ur a..was it 4.9.....?????

Yes it was.

 

[hassam]

come on XPF CHAT....i want to finish it off....today....i cnt prepare properly for next exams....thousgh they are mcqs

 

[BILALrox01]

@gatechatl........if u hav got senses....which i dont think u hav....a samller drop will hav a smaller mass....ryt...?...so is it so hard to conceptualize....and u tell me wat assumption i made

He "hav got senses". It was never mentioned in the paper that the mass of the raindrop decreases, hence you shouldn't assume so. Yes, the volume has decreased, but you have seen in the past papers, that water could have different densities, eg water vapour @ 1/1600 kgm^-3 and water @ 1000kgm^-3. This means that the mean separation between the molecules has decreased, but the mass has not decreased. Have you actually payed attention to the past papers you have done?

actually.. ur assuming too much.. they never gave us the mass.. they only gave the density.. Since density remains constant.. voume decrease results in mass decrease..

 

[BILALrox01]

AM I THE ONLY ONE WHO GOT 2.6 FOR THE CURRENT ?

yes u r..

 

[Ismail Breiwish]

@gatechatl........if u hav got senses....which i dont think u hav....a samller drop will hav a smaller mass....ryt...?...so is it so hard to conceptualize....and u tell me wat assumption i made

He "hav got senses". It was never mentioned in the paper that the mass of the raindrop decreases, hence you shouldn't assume so. Yes, the volume has decreased, but you have seen in the past papers, that water could have different densities, eg water vapour @ 1/1600 kgm^-3 and water @ 1000kgm^-3. This means that the mean separation between the molecules has decreased, but the mass has not decreased. Have you actually payed attention to the past papers you have done?

actually.. ur assuming too much.. they never gave us the mass.. they only gave the density.. Since density remains constant.. voume decrease results in mass decrease..

Yes, it is, but what I said later on explains that the change in the density COULD be a reason why the mass MAY or MAY NOT remain constant. I reiterated the fact that I used only the information they gave us in later posts ie the expression for resistive force. My statement that you have quoted is not an assumption I made while doing the exam.

 

[Ismail Breiwish]

Well both of your are working on assumptions. It said radius decreased
so surface area of the rain drop decreased too. Lesser resistance.
hence greater terminal velocity and more time taken to reach terminal velocity.
Simple. Both are in similar states hence density must be the same. hence mass of the second raindrop
should be more. Again whenever the mass is greater terminal velocity is more
since resultant downard force is more
Hope that clears

I have said it once, and I'll say it again : I DID NOT MAKE THOSE ASSUMPTIONS. I used the information that was given in the exam, which is the aim of such a question, to test our aptitude with UNFAMILIAR subjects by applying FAMILIAR concepts.