Big Ideas of the Unit 1. All fluids demonstrate the property of viscosity, or the internal friction that causes a fluid to resist flowing 2. Density is an important property of fluids 3. Fluids exert a buoyant force on objects that causes objects to float 4. Understand the properties of fluids that helps in the design and construction of useful devices

What is a Fluid? Fluids include liquids AND gases They are substances that are able to flow and take shape of a container Make oobleck using 1 part water : parts cornstarch (ie if you use two tablespoons of cornstarch, you will need about one tablespoon of water) What are the characteristics that make it a fluid? What are the characteristics that make it a solid?

1.1 Investigating Viscosity Particle theory of matter: Solid matter have particles that are close together and in a ‘fixed’ position Liquid matter have particles that are still close together but the particles can ‘slide’ around Gaseous matter have particles that are far apart and move quickly

Can we make a new definition that included the particle theory? Points to consider- Fluids can be poured Fluids take the shape of the container How can we add in the particle theory?

SAFETY and WHMIS Most fluids are safe and we interact with them everyday However some fluids can be dangerous and they are labeled using the WHMIS system (Workplace Hazardous Material Information System) Fill in the WHMIS symbols

Viscosity One property of fluids is how they flow How fluids flow is determined by its viscosity Viscosity is how easily a liquid flows High viscosity= doesn’t flow well (ketchup) Low viscosity= does flow well (apple juice) Viscosity can be determined using the bubble test or the ramp test (pour down a ramp and see which fluid is the fastest)

Activity Bubble test- test various liquids to see which has the most viscosity Higher viscosity= longer time for the bubbles to rise up Wrap-up discussion As a group discuss the results and answer the questions

Viscosity is Important What causes viscosity? Particles are attracted to each other and this attraction will determine how easily the particles ‘slide’ around A strong attraction means the particles can not move as much (think about a solid, the particles have a strong attraction to each other) Demo- jar of marbles vs a jar of yarn. The yarn is attracted to the other yarn and do not move much as a result Write out a paragraph describing viscosity- use the words: fluid, particles, flow and viscosity in your explantion