SMS 204: Integrative Marine Sciences, Physics & Chemistry

1. SMS 204: Integrative Marine Sciences, Physics & Chemistry • Instructors: E. Boss & M. J. Perry • Office hours: upon appointment E. Boss is usually available following labs and on Thu am. • Final: Monday, May. 5th, 1:10pm • Class web site: http://misclab.umeoce.maine.edu/boss/classes/SMS_204_2008/Syllabus.htm SMS 204: Integrative marine sciences

2. Some important concepts from last week: • No-slip • Treatment of fluid as Continuum • Viscosity • Q. 5 on quiz 1. SMS 204: Integrative marine sciences

3. Mass, volume and density. • In fluids we often cannot follow a coherent mass. • Conservation of mass is described by mass continuity (incompressible flows): • Mass flux: rvA [Kg/sec], Av • How do you get a hose to squirt further? SMS 204: Integrative marine sciences

4. Density and water movement: • What happens when: • Dense water is above less dense water? • Dense water is next to less dense water? Demo • What about: SMS 204: Integrative marine sciences

5. Density stratification across the Pacific Ocean SMS 204: Integrative marine sciences

6. Newton’s laws of motion: • Without force a body will continue its motion • d(momentum)/dt=Force • When a body 1 applies a force on body 2 an equal and opposite force is applied on body 1 by body 2. • Momentum=mv • Momentum flux=mass flux*v= • rv2A [Kgm/sec2], Av • Note: v-velocity, V-volume SMS 204: Integrative marine sciences

7. Pressure and stress: • Force per unit area • Sharp vs. blunt objects • Within a fluid pressure is * while the force due to it is  to the container’s walls (Demo). • Hydrostatic pressure: the weight (divided by A) of the fluid above- Mg/A=rgh (for constant r) Problem solving in class Average pressure on a Dam, force on a diver’s face In class demonstration: squirting column SMS 204: Integrative marine sciences

8. Fluid moves from high to low pressure: F=ma  dv/dt=F/m=F/(ALr)  dv/dt=-r-1dp/dx In class demonstration: the monometer Pump: a device that moves fluid by changing pressure within a fluid. Pumps in biological systems (positive displacement): Heart- circulates blood by changing the volume in its chambers (what does the work?). Siphon (e.g. straw)- mollusks http://www.fws.gov/midwest/mussel/multimedia/posters/mussels_of_minnesota_back.pdf SMS 204: Integrative marine sciences

9. Application: the hydraulic press Figure from: http://hyperphysics.phy-astr.gsu.edu/hbase/pasc.html#pp SMS 204: Integrative marine sciences

10. Equation of state of water: relates density to other variables (S, T & P). Density vs. T and P: From: http://geoserv.geology.wmich.edu/dave SMS 204: Integrative marine sciences

11. Equation of state of an ideal gases • PV=nRT • Linking temperature and kinetic energy of molecules. • Linking pressure to momentum transfer (normal) to sides of container. • Linking viscosity to momentum transfer between molecules. • In class demonstration (change of volume with pressure) SMS 204: Integrative marine sciences

12. Diving and pressure • Equalizing pressure in cavities. • Why we can’t snorkel deep? Why does SCUBA works? • Gas solubility and pressure. • How do some marine mammals prevent lungs from collapsing? http://www.iantd.com/rebreather/phys.html SMS 204: Integrative marine sciences