Maths & Physics Help

[emi]

i dont get the part why u used the Pythagoras theorem to get the answer  . 

=(

[astarmathsandphysics]

The first man is east of the pole and the 2nd man is |South. Between South and east the angle is 90 degrees - a right angle.

[emi]

thank you

i got it now =D

[emi]

i dont know how to solve this Question ,,

Q: The sum of two numbers is 131. Twice of one number is 5 less than the other . find the numbers

at the back of the book answers are " 42 and 89 "

[sweetsh]

let me answer it for you.

By simultaneous equations.

Let the numbers are x,y

x+y=131
this is equation (1)
now.. 2x-y=5
as 2x+5=y

now solve it.
you will get x=42 and y=89

[astarmathsandphysics]

Thanks. I find thesex questions hard to answer on a mobile phone.

[emi]

thanks i solved it now =D

[sweetsh]

Youuu welcome

[hyebyekadal]

OK guys I did some phy papers and I had some doubts (this is paper 3 2008 June , 2nd vairent)
1.One of the laws about the behaviour of gases states that
“For a fixed amount of gas at constant temperature, the pressure is inversely proportional
to the volume”.
In the space below, write an equation that represents this law.

So i wrote P=1/V
but the ms says that NOT correct and the correct ans is pV=constant

2.Explain, in terms of molecules, how thermal expansion takes place in a solid and in a
gas.
P.S. I got the gas part, need hwlp on the solid part.
Sold:
My ans:The molecules gain more kinetic energy and and vibrate more annd faster. Thus the molecules require greater space.
MS:SOLID higher temperature means higher energy/greater speed of
mols/particles/atoms
NOT more vibration NOT vibrate more

[astarmathsandphysics]

OK guys I did some phy papers and I had some doubts (this is paper 3 2008 June , 2nd vairent)
1.One of the laws about the behaviour of gases states that
“For a fixed amount of gas at constant temperature, the pressure is inversely proportional
to the volume”.
In the space below, write an equation that represents this law.

So i wrote P=1/V
but the ms says that NOT correct and the correct ans is pV=constant

2.Explain, in terms of molecules, how thermal expansion takes place in a solid and in a
gas.
P.S. I got the gas part, need hwlp on the solid part.
Sold:
My ans:The molecules gain more kinetic energy and and vibrate more annd faster. Thus the molecules require greater space.
MS:SOLID higher temperature means higher energy/greater speed of
mols/particles/atoms
NOT more vibration NOT vibrate more

should be P=k/v which is equivalent to PV=k
2. When a solid is heated the molecules vibrate against each other and push each other apart.

[SGVaibhav]

i wanted notes for states of matter

[astarmathsandphysics]

There are some more gcse-igcse activbooks up now on www.freeetextbooks.com

[hyebyekadal]

um...astar i dint get what u mean about the expansion... so how come the ms disapproves it??
thanx again for answering anyway!

[astarmathsandphysics]

The molecules in the solid vibrate more so push each other further apart on average.

[nid404]

The second part of the question needs help.
Q.The air in a bicycle tyre has a volume of 1000cm3 and a pressure of 2.5 atmospheres. If the air is released ( at the same temperature) so its pressure is 1 atmosphere, what is the volume of the air?

This part needs help

A bicycle has a volume of 100cm3 and is now used to pump up the tyre. After 1 stroke of the pump, what is the presure in the tyre?

Thanks