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BMS1031 (Fluids and Energy and Cardiovascular Weeks 1 to 5 (Energy, Work,…

- - - - The relationship between an objects mass m , its acceleration a, and applied (net) force F=ma. :red_flag:
      - For every action there is an equal and opposite reaction.
      - An object stays in its state of rest (or of uniform motion in a straight line) as long as no net force acts on it.
    - - Kinetic friction; sliding friction. An experimental relationship between the magnitude of the friction force which acts parallel to the two surfaces and the magnitude of the normal force. :red_flag:
      - Static friction; force parallel to the two surfaces that can arise even when they are not sliding. :red_flag:
  - - - Hydrostatic Pressure in Fluids
        P = pgh :red_flag:
        The pressure in a fluid is proportional to the depth in the fluid.
      - Atmospheric Pressure at sea level =
        101.3kPa (1atm)
      - Measuring pressure;
        absolute versus gauge pressure.
        Pressure gauges measure the difference between two pressure, gauge pressure.
        In a manometer pressure absolute = Patm + Pg
      - Mercury as a measurement tool:
        1mm Hg = 133Pa = 133 N/m2
      - P=F/A
        1 Pa = 1N/m2
    - - Archimedes Principle:
        Buoyancy force is equal to the weight of the fluid displaced. :red_flag:
      - For an object suspended in water:
        Upward Force = Downward Force
        T + F buoyancy = mg
        Can be used to determine volume and density of an object.
    - - Viscosity; a frictional force between adjacent layers of fluid as the layers move past one another.
      - Mass flow rate continuity:
        pAv = pAv = Q :red_flag:
        For two points in a flowing fluid.
        
        Flow in tubes is a specific example of the concept of continuity.
        Poiseuilles Equation
        Q = (change P.Pi.r^4)/(8.viscocity.length of tube) :red_flag:
        For flow in a tube of uniform radius and assumes laminar and incompressible flow.
      - Bernoulli Equation and the conservation of flow energy
      - Surface tension; the surface of a liquid acts like it is under tension and this tension acting along the surface arises from the attractive forces between molecules.
      - Sedimentation; a particle falling in a liquid / fluid experiences gravitational force down, a buoyant force Fb and a drag force D up due to viscosity.
        Drag force = k.r.v where k is a constant :red_flag:
        Sedimentation is faster for larger r, larger object p, or larger g.
  - - - Kinetic Energy
        Ek = 0.5mv^2 :red_flag:
      - Gravitational Potential Energy
        Ep = mgh :red_flag:
    - - Thermal energy = atoms and molecules kinetic and potential energy
      - Q = m.c.change in T :red_flag:
        c (J kg-1K-1)
        Storing heat in an object doesn't only depend on the specific heat but the mass as well
      - Energy is required for a material to change phase even though its temperature is not changing. The amount of heat required for a phase change is called latent heat = mL :red_flag:
        E.g. if you want to break the bonds of water molecules you have to put heat in to break the bonds.
      - Heat Transfer
        
        Convection
        Movement of heat flows by the mass movement of molecules. Natural convection is due to the lower density of hotter fluids.
        E.g. main use of heat transfer by the body.
        
        Thermal radiation a form of electromagnetic wave due to oscillations of electrons / electric charges.
        Stefan-Boltzmann Equation :red_flag:
        Emission and absorbtion
        
        Conduction E.g. cooking on a frying pan.
        (change heat / change time) = kA (T1-T2)/l :red_flag:
        heat transfer decreases by 1/l
        (W.m.K)
        
        First Law of Thermodynamics
        Change in energy (Kinetic, Potential, internal energy) = Heat in - Work done
        In a closed system the internal energy changes only as a result of heat flow or work done. In an open system (such as human) internal energy itself can flow into and out of the system.
        Typical metabolic rates - the rate at which internal energy is transformed within the body.
        Basal metabolic rate is the rate at which energy is produced when a person is totally resting
  - - - Charles Law; V1/V2 = T1/T2
      - Ideal Gas law; PV = nRT
        Where R = 8.315 J mol-1 K-1
      - Boyle's Law; P1V1 = P2V2
    - - Osmosis equalises water partial pressure
        P water left + P solute left = P water right + P solute right
      - Tonicity
        
        Isotonic; equal
        
        Hypotonic; water flowing out of solution
        
        Hypertonic; water flowing into solution
    - - Henry's Law
        The equilibrium concentration of dissolved gas is proportional to the partial pressure of that gas in gas above the liquid.