Ch. 11 Forces in Fluids

1. Ch. 11 Forces in Fluids

2. Pressure • Pressure-force per unit area on a surface • Unit of measurement: pascal (Pa): 1 N/m2 • A fluid is any substance that can easily flow -liquids and gases

3. Fluid Pressure • The particles of a fluid are in constant motion • All of the forces exerted by the individual molecules in a fluid added together make up fluid pressure

4. Balanced Pressures • We don’t feel “crushed” by the atmosphere because the pressure is balanced with the pressure your body is exerting outward

5. Variations in Fluid Pressure • Pressure and elevation Air pressure decrease as elevation increases

6. Variations in Fluid Pressure • Pressure and depth Water pressure increases as depth increases

7. Pascal’s Principal • When force is applied to a confined fluid, an increase in pressure is transited equally to all parts of the fluid

8. Floating and Sinking Buoyancy Force- acts in the upward direction, against the force of gravity, so it makes an object feel lighter

9. Archimedes’ Principle The buoyant force of an object is equal to the weight of the fluid displaced by the object

10. Bernoulli’s Principle The pressure exerted by a moving stream of fluid is less than the pressure of the surrounding fluid

11. Bernoulli’s Principle