Corrigé des exercices : pression hydrostatique p= . g . h

1. p = 1025 . 10 . 10 = 102500 Pa

2. p = 1025 .906 .10 = 9286500 Pa

3. h = 510000/(10 . 1000) = 51 m

4. pN = 665 . 10 . 0,1 = 665 Pa pE= 1000 . 10 . 0,2 = 2000 Pa et p = 665 + 2000 = 2665 Pa

5. pHg = 13600 . 10.0,1= 13 600 Pa et palc = pHg= 800 . 10 . h => halc = 13 600 / 8000 = 1,7 m

6. h = 15000 / (790 .10) = 1,89 m

7. p = 6900 .10. 0,78 = 53820 Pa

8. p= 1000 .10.20 = 200000 Pa

9. h = 1 500 000/(1025.10)= 146 m

10. pEau = 1000.10.0,08 = 800 Pa => palcool = 800 = 800 . 10 . halc => halc = 0,1 m= 10 cm.

force pressante F = . g . h . S car F = p.S et p= . g . h

1. F = 1000 . 10 .0,25 . 0, 03 = 75 N

2. F = 1000 . 10. 60 .1 = 600 000 N

3. VHg= 2L h = V/S h = 2000cm³/200cm²= 10 cm= 0,1m

Veau= 4L h = V/S h = 4000cm³/200cm²= 20 cm= 0,2m

Ftotale = FHg + Feau = 13 600 . 10 . 0,1 . 0,02 + 1000 . 10 . 0,2. 0,02 = 272 + 40 = 312 N

4. S = . 0,1 ²

=> F = FHg + F chloroforme = 13600 . 10 . 0,1 . 0,1² . + 1489 .10 . 0,2 . 0,1² . = 520,5 N

5. F = 1000 . 10 .30 . . 0,9² = 763 407 N

6. F = 1025 . 10. 8,95 . . 0,45² = 58 360 N