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Fluids and Structures Review. What is a fluid?. A fluid is something that flows and can be a liquid or gas. The two most common fluids are water and air. Name the three key points to the Particle Theory. All matter is made up of particles. Particles are in constant motion.
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A fluid is something that flows and can be a liquid or gas. The two most common fluids are water and air.
All matter is made up of particles. • Particles are in constant motion. • There are forces of attraction between particles.
Laminar flow is the movement of a fluid in a straight or almost straight line. • Turbulent flow is the movement of a fluid in a broken or choppy pattern.
Viscosity is the resistance a fluid has to flowing and movement.
A thick fluid has a high viscosity and a slow flow rate. A thin fluid has a low viscosity and a high flow rate.
Order these substances from greatest to least flow rate: ketchup 1.5 mL/s water 6.5 mL/s corn syrup 0.3 mL/s
The order for greatest to least flow rate is: Water, ketchup and corn syrup
Mass is the amount of matter in an object and remains constant. Weight is a measurement of the force of gravity pulling on the object. It varies because gravity is different depending on where you are in the universe.
Buoyancy is the upward force that acts on an object. Gravity is the downward force that acts on an object.
Order these substances from least to most dense: Salt 2.16 g/mL Silver 10.5 g/mL Salt water 1.03 g/mL Ice 0.92 g/mL
The order from least to most dense is: Ice, salt water, salt and silver
The three types of buoyancy are positive buoyancy, neutral buoyancy and negative buoyancy.
What is the difference between a hydraulic and pneumatic system?
A hydraulic system is a confined system that uses a liquid under a high pressure. A pneumatic system is a confined system that uses air under a high pressure.
Lever • Wheel and axel • Pulley • Screw • Inclined plane • Wedge
A fixed pulley changes the direction of the force. A moveable pulley multiplies the force.
Friction is a force that opposes movement. So friction makes things less efficient reducing a machine’s mechanical advantage.
The three types of friction are rolling, sliding and fluid friction.
What would be the mechanical advantage of a lever that can lift 80N with an effort of only 20N?
Mechanical Advantage = load force ÷ effort force • MA = 80N ÷ 20N = 4
How much pressure would be placed on a surface with an area of 2m2 if an object weighing 500N were sitting on it?
Pressure = Force ÷ Area = 500N ÷ 2 m2 = 250 N/m2