Maths & Physics Help

[astarmathsandphysics]

Post your GCSE questions here to get the answers back asap from someone with 3 maths/physics degrees.

[nid404]

I tried starting a new topic but it's not working for me. Anyways plz help me
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

[spookyjaransh]

the constant here is = (1000/2.5) =400.
there fore after 1 stroke the volume increases by 100 cm3, thus new volume = 1100.
but because the constant does not change, therefore, 1100/x = 400
=> x = 1100/400 = 2.75 atm.

[astarmathsandphysics]

How did I miss this question for so long

[~~~~shreyapril~~~~]

hm..!!
i guess you did not notice it!!
u are too busy person rite??

[astarmathsandphysics]

v busy

[@d!_†oX!©]

the constant here is = (1000/2.5) =400.
there fore after 1 stroke the volume increases by 100 cm3, thus new volume = 1100.
but because the constant does not change, therefore, 1100/x = 400
=> x = 1100/400 = 2.75 atm.

hey ansh!!!
u've done one thing wrong here....
according to the boyle's law constant = pressure*volume
so, k=1000*2.5 = 2500
thus,
p= k/v
=>p=2500/1100
=>p=2.27 atm

am i right sir???

[astarmathsandphysics]

You were supposed to work out the volume of the air I think when the pressure is reduced from 2.5 atm to 1.

[Ghost Of Highbury]

is it 2500/2600 = 0.9?

[@d!_†oX!©]

that was the first part...i think nid said she wanted help in the second part...

[@d!_†oX!©]

is it 0.9?

u talking abt the first or second part??

[Ghost Of Highbury]

I tried starting a new topic but it's not working for me. Anyways plz help me
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

its ritten the second part needs help.

[spookyjaransh]

so wats the correct answer then??

[astarmathsandphysics]

pV=k so 2.5*1000=k so V=2500/p but p is now 1atm so V=2500cm£

Some of the air escaped to the atmosphere

[@d!_†oX!©]

sir cud u do the second part as well??