Elasticity and Fluid Physics

1. Elasticity and Fluid Physics Karl Andre O. Ortiz

2. Chapter objectives • Familiar with the different properties of matter • Differentiate between stress and strain • Learn how man harnessed the concept of pressure to invent and develop useful applications • Distinguish hydrostatics from aerodynamics • Show how airplanes fly using the concept of aerodynamics

3. Matter -it is the substance of which all objects are made -it also can be changed into energy and energy into matter -has mass and occupies space -has many forms

4. Structure of Matter Matter is composed of tiny particles called molecules and in these structures, ATOMS linked together consist it. ATOMS are made up of particles called protons, neutrons, and electrons. Protons- positively charged Neutrons- electrically neutral Electrons- negatively charged These particles are composed of point-like units called QUARKS. Particles smaller than atoms are called sub atomic particles

5. Differences between electric charge holds the atom togetherelectrons whirl around the nucleusin lavers called electron shellsthe outermost shells are not tightly bound to the nucleus,as a result some outermost electrons can be shared. Theseelectrons are called IONS

6. MATTER has many forms 3 basic states: • Solid • Liquid • Gas

7. Other states of matter • Plasmas • Superfluids • Superconductors • Bose-Einstein Condensates • Antimatter or Darkmatter

8. Chapter objectives Familiar with the different properties of matter • Differentiate between stress and strain • Learn how man harnessed the concept of pressure to invent and develop useful applications • Distinguish hydrostatics from aerodynamics • Show how airplanes fly using the concept of aerodynamics

9. Density and Specific Gravity Density is the mass or the specific amount of matter in an object. D = M/V Where: M is mass V is volume

10. Density in Solids • Regularly shaped • Irregularly shaped Density in Gases Is difficult to measure Mass – First weigh an empty container. Next, fill the container with the gas and weigh it again. Then subtract the first measurement to the second Volume – measure the amount of water that the container can hold

11. Stress and Strain Tensile stress – the ratio of the applied force F to the cross-sectional area A Stress = Force/Area = F/A Tensile strain – defined as the ratio of the change in length ΔL to the initial length Lₒ before the force was applied. This strain refers to the change in length Strain = change in length/initial length = ΔL/Lₒ

12. Young’s Modulus of Elasticity – the amount of strain an object undergoes depends on the amount of stress applied to it. Y = stress/strain = (F/A)/(ΔL/Lₒ) The ratio of stress to the corresponding strain

13. Elastic Limit - refers to the maximum stress that can be applied to an object without its breaking up, or being permanently deformed

14. Chapter objectives Familiar with the different properties of matter Differentiate between stress and strain • Learn how man harnessed the concept of pressure to invent and develop useful applications • Distinguish hydrostatics from aerodynamics • Show how airplanes fly using the concept of aerodynamics

15. Fluid Statics When a fluid is at rest the forces exerted are those due to the static conditions • Hydrostatics • Pressure • Buoyancy

16. Pressure in Fluids Pressure is a force exerted over an area and is measured in Pascals(Pa) P (in Pa) = Force (in newtons) Area (in m²) Absolute pressure = gauge pressure + atmospheric pressure

17. Three properties of pressure in a Fluid • The forces of fluids at rest exert on the walls of its container, and vice versa, and always act perpendicular to the walls. • An external pressure exerted on a fluid is transmitted uniformly throughout the volume of the liquid (Pascal’s Principle) • The pressure on small surface in a fluid is the same regardless of the orientation of the surface