Tips & Formulas Fluid Statics

University:
Concordia University Wisconsin
Course:
PHYS 1514 | General Physics I
Academic year:

2023
Views:

179

Pages:

2
Author:

Leland Liu

MECHANICAL PROPERTIES OF MATTER FLUID STATICS mass volume 1. Density = 2. Specific weight = 3. Relative density = density of pure water 4o C 4. Density of a Mixture of substance in the proportion of mass weight  g volume density of given liquid M1  M 2  M 3 ..... the density of the mixture is   M M M 1  2  3  .... 1 2 3 5. Density of a mixture of substance in the proportion of volume 1 V1  2 V2  3 V3 the density of the mixture is   V  V  V  .... 1 2 3 normal force area 6. Pressure = 7. Variation of pressure with depth Pressure is same at two points in the same horizontal level P1 = P2 The difference of pressure between two points separated by a depth h (P2 – P1) = hg 8. Pressure in case of acceleration fluid (a) Liquid placed in elevator : When elevator accelerates upward with acceleration a0 then pressure in the fluid, at depth h may be given by, P =h[g + a0] a0 h (b) Free surface of liquid in case of horizontal acceleration : tan   ma 0 a 0  mg g If P1 and P2 are pressure at point 1 & 2 then P1 – P2 = g (h1 – h2) = gl tan   l a 0 (c) Free surface of liquid in case of rotating cylinder h v 2 2 r 2  2g 2g 9. Pascal`s Law 10. Types of Pressure 11. The pressure in a fluid at rest is same at all the points if gravity is ignored. A liquid exerts equal pressures in all directions. If the pressure in an enclosed fluid is changed at a particular point, the charge is transmitted to every point of the fluid and to the walls of the container without being diminished in magnitude. [for ideal fluids] Pressure is of three types (a) Atmospheric pressure (P0) (b) Gauge pressure (Pgauge) Atmospheric pressure Force exerted by air column on until cross-section area of sea level called atmospheric pressure (P0) (c) Absolute pressure (Pabo.) up to top of atmosphere 2 F air area=1m = 101.3 kN/m2 column sea A level P = 1.013 × 105 N/m2 Barometer is used to measure atmospheric pressure. Which was discovered by Torricelli. Atmospheric pressure varies from place to place and at a particular plac from time to time. Po = 12. Gauge Pressure Excess Pressure ( P – Patm) measured with help of pressure measuring instrument called Gauge pressure. Pgauge  hg or Pgauge  h Patm manometer g as Pabsolute h Gauge pressure is always measured with help of “manometer” 13. Absolute Pressure Sum of atmospheric and Gauge pressure is called absolute pressure. Pabs  Patm  Pgauge  Pabs  Po  hg The pressure which we measure in our automobile tyres is gauge pressure. Buoyant force = Weight of displaced fluid = Vg 14. 15. 16. Apparent weight = weight – Upthrust 17. Relative density of body = Density of water Rotatory – Equilibrium in Floatation : for rotational equilibrium of floating body the meta-centre must always be higher than the centre of gravity of the body. Density of body