p1=p0=75cmHg v1=48s T1=300KP2=P0+Lsin30^0=87.5cmHg v2=75s-25s=50s T2=?由P1V1/T1=P2V2/T2T2=87.5x50x300/75x48=364.6k升高△t=T2-T1=64.6^0C