Physics reasonable estimates? :/

[Mssamgirl15]

Okay so there's this question in Oct/Nov 2010 paper 23.
Q: Make estimates.
a) thickness of a sheet of paper
b) time for sound to travel 100m in air.
c) the weight of 1000cm^3 of water

part b can be easily calculated but HOW THE HELL do we do parts a) and c) ??
PLEASE HELP!!

 

[yasser37]

u need to estimate!
paper shud be like 0.5 mm or something like that
1000 cm^3 of water is 1 litre which is about 1 Kg I guess

 

[abdhot7]

thickness = about 0.5mm
and the weight is easy as well 1000cm^3 = 1000g = 1kg
nd the weight of 1 kg is 1*9.81=9.81N
easy enugh

 

[sniper7137]

I hate estimations. Its pretty damn easy to make a mistake here. Just common sense and experience i guess. But make sure you go through the frequencies and wavelengths of the electromagnetic spectrum. They are usually quite problematic. :good:

 

[Feelguud77]

But theres a pretty large range of values!

 

[Mssamgirl15]

They don't always have a huge range. For thickness, the range is from 0.05 to 0.15mm and the weight of 1000cm^3 of water should be between 8 and 10N. But yeah if the ask us to estimate the frequencies and wavelengths of the electomagnetic spectrum, then it's all good but if they ask us something random like ' the number of gas molecules in a room', I'll pull my hair out. :/

 

[arlery]

Refer to this thread:

viewtopic.php?f=26&t=7747

 

[Feelguud77]

They don't always have a huge range. For thickness, the range is from 0.05 to 0.15mm and the weight of 1000cm^3 of water should be between 8 and 10N. But yeah if the ask us to estimate the frequencies and wavelengths of the electomagnetic spectrum, then it's all good but if they ask us something random like ' the number of gas molecules in a room', I'll pull my hair out. :/

No kiddin raiet but no, they dont ask stuff like that! *pause* i HOPE thet don't

 

[Mssamgirl15]

Aaaargh! Physics makes me mad.

 

[Feelguud77]

Its like, every paper has 1 hour 15 minutes, and to top it all off, PHYSICS has ONE hour only!

 

[Mssamgirl15]

I knowwww. One hour is nothing. Physics should actually get more time since it requires extensive thinking.

 

[princesszahra]

Okay so there's this question in Oct/Nov 2010 paper 23.
Q: Make estimates.
a) thickness of a sheet of paper
b) time for sound to travel 100m in air.
c) the weight of 1000cm^3 of water

part b can be easily calculated but HOW THE HELL do we do parts a) and c) ??
PLEASE HELP!!

as the question says!! estimate it!!!!!!!!!!!!
u can learn these values + mass of apple , ruler , earth

 

[Feelguud77]

Exactly! how can a theory paper have the same time as that required for its MCQ counterpart