1. Study of Fluids

2. Types of Fluids Incompressible compressible

3. Fluids mechanics classifies into two Fluids at rest Fluids in Motion

4. Two kinds of Density Units Kg/m 3 N/m 3 Density of water is constant ρ w = 1000 kg/m 3 or 1 g/cm 3

5. Density of some substance

6. Unit Pure number Sp.Gr w = 1

7. Unit: N/m 2 F A p F A p = SI Unit: Pascal or P a 1 N/m 2 = 1 P a

8. PaPa

9. (p+dp)A pA dw pA – (p+dp)A - dw =0 ΣF y = 0 pA–(p+dp)A-ρgdV=0 pA–(p+dp)A-ρgAdy=0 dp dy =-ρg-ρg p 2 –p 1 = -ρg(y 2 – y 1 ) dp= -ρgdy p 2 –p 1 = -ρgh

10. dp dy =-ρg-ρg p 2 –p 1 = -ρg(y 2 – y 1 ) dp= -ρgdy p 2 –p 1 = -ρgh p 1 = p 2 +ρgh p = p 0 +ρgh

11. p - p 0 = ρgh

12. “Pressure applied to an enclosed fluid is transmitted undiminished to every portion of the fluid and the walls of the containing vessel.” p p pp p p

14. h PaPa P ab P ab = P a + P g P ab = P a + ρgh Where: P ab = absolute pressure P a = atmospheric pressure P g = ρgh gauge pressuref

16. Ans. 61.6 N 1. Ans. a) 706 Pa, b) 3.16x10 3 Pa 2.

17. 3. Fig. below Ans. 10.9

18. Archimedes’ Principle states “When a body is completely or partially immerged in a fluid, the fluid exerts an upward force called buoyant force on the body equal to the weight of the fluid displaced by the body.”

19. Ans. a)7.84 N, b) 139 Fig. below.