P 1=P0

V 1=LS

After putting a small weight with a mass of m on the piston, balance it according to the force on the piston:

mg+P2S=P0S？ Solution: P2 = P0+MGS? ①

When the balance is reached, let the height difference between the mercury surface inside and outside the tube be h,

So p2 = P0+rhogh? ②

① ② Simultaneous: h = mρ s

The state volume of gas becomes

V2=L2S

According to Boyle's law,

P2L2S=P 1LS？ ③

Gas heating makes the length of the gas column return to the constant pressure change in the process of l,

Yugai? Lussac's law: l2st0 = lst④.

① ③ ④ At the same time:

T=( 1+mgP0S)T0

In this process, the temperature of the gas rises.

△t=T-T0=( 1+mgP0S)T0？ T0=mgP0ST0

So the answer is: mρS, mgP0ST0. ..