17. 1h30ph=5400s
[tex]P=\frac{A}{t}=\frac{P.h}{t}=\frac{Dn.V.h}{t}[/tex]
=> V=...
[tex]P=\frac{A'}{t}=\frac{P'.h'}{t}=\frac{Dn.V'.h'}{t}[/tex]
=> V'=...
18.
Fci.l=P.h => Fci=...
Ftp=Fci+Fms=...
Aci=Fci.l=...
Atp=Ftp.l=...
[tex]H=\frac{Aci}{Atp}.100=...[/tex]