Capter 2

1. Capter 2 Fluids

2. Hidrostatik Prinsip Pascal Hukum Hidrostatika Prinsip Archimedes Kekentalan Tegangan Permukaan Kapilaritas Hidrodinamik Persamaan Kontinuitas Prinsip Bernoulli Fluida

3. Massa Jenis Massa jenis sebuah bahan didefinisikan sebagai massa persatuan volume Volume sama tetapi massa bisa berbeda

4. Tekanan • Tekanan didefinisikan sebagai gaya per satu satuan luas

5. Tekanan Atmosfir • Tekanan atmosfir disebabkan karena berat udar di atas kita • Besar dan satuan dari tekanan atmosfir Po = 1,01 x 105 N/m2. 1 atm = 76 cmHg = 1.01 x 105 Pa

6. Tekanan Hidrostatik Po Tekanan di dasar bejana disebabkan karena tekanan udara di permukaan zat cair dan berat zat cair di atasnya h P=Po + rgh

7. Prinsip Pascal Tekanan yang diberikan pada zat cair dalam ruang tertutup akan didistribusikan ke semua bagian dengan sama besar. Perbandingan luas penampang A 1 dan A2 pada bejana menghasilkan pelipatan gaya antara F1 dan F2

8. Archimedes’ Principle • When a body is immersed in a fluid, the fluid exerts an upward force (buoyant force) on the body whose magnitude is equal to the weight of the fluid displaced by the body. Archimedes’ principle is mathematically formulated of F = rfluid V . g Where : F is buoyant force, r fluid is density of fluid, and V is the volum of immersed body The differentiation of the object’s weight, when it measured in the air and in the fluid, is caused by archimedes’ force

9. Three possible cases of a body in a fluid : Floating rb < rfluid Barely Floating (completely submerged) rb =rfluid Sinking rb > rfluid

10. Student Activity • Find the pressure increase in the fluid in a syringe when a nurse applies a force 42 N to the syringe’s circular piston which has a radius of 1.1 cm

11. Student Activity • Calculate the hydrostatic difference in blood pressure between the brain and the foot in a person of height 1.83 m. The density of the blood is 1.06 x 103 kg/m3

12. Student Activity • A drum of 1 meter high is filled with kerosene ( r = 0.8 g/cm3). To ¾ of the drum’s height. If g = 10 m/s2 find the pressure at the bottom of the drum

13. Student Activity • Given the density of ice is 920 kg/m3 and density of seawater is 1,030 kg/m3. what fraction of the ice’s volume will be dipped into the sea

14. Student Activity • A piston cross-section area a is used in a hydrolic press to exert a small force of magnitude f on the enclosed liquid. A connecting pipe leads to a larger piston af crosssection area A (see on the figgure), what force magnitude F will the larger piston sustain without moving ? If the piston diameters are 3.80 cm and 53.0 cm. what force magnitude on the small piston will balance a 20.0 kN force on the large piston ?

15. Student Activity • An iron anchor of density 7870 kg/m3 appears 200 N lighter in water than in air. (a) what is the volume of the anchor ? (b) How much does it weigh in air.

16. Student Activity • A block of wood floads in fresh water with two-thirds of its volume submerged and in oil with 0.90 V submerged. Find the density of (a) the wood and (b) the oil