Show:
Fluids and Pressure
Buoyant Force
Fluids and Motion
Surprise 1
Surprise2
100
Force divided by area equals this.
What is pressure
100
The upward force on an object submerged in a fluid
Buoyant Force
100
Upward force on an object in a moving fluid
Lift
100
Measure of the force of gravity on an object
Weight
100
What happens to water pressure as depth increases?
Increases
200
Define Fluid.
Anything that can flow and takes the shape of the container
200
Changes in this cause a submarine to dive or rise
Mass of submarine/Overall density
200
What does Bernoulli's Principle say
Fluid pressure decreases as its speed increases
200
What are the four main forces acting on a plane in flight? What does each force do (in what direction does it act)?
Lift--push plane upwards Weight--push plane down Thrust--Push plane forward Drag--slow plane down
200
What happens to the pressure inside the shower when the water is running?
Decreases
300
In what direction does fluid pressure act?
Evenly in all directions
300
What does Archimedes' Principle say?
Buoyant force equals weight of displaced fluid
300
Why do racing cars have spoilers (upside down wings)?
Help keep the car down. Air pressure above the upside down wing is higher than below it, pushing it down.
300
SI unit for Pressure is ______ or _______
Pa, N/m^2
300
What causes atmospheric pressure
Weight of the air column
400
Explain why at the same depth, water pressure is greater than air pressure.
Water is denser than air
400
What causes buoyant force in a fluid?
Pressure differences (pressure increases with depth)
400
Explain why a paper will get stuck to the back of a fan that is on but not to the back of the same fan if it is off.
When on, air inside is moving fast, low pressure zone. Outside is high pressure zone, so paper is sucked in. When off, no pressure difference so paper doesn't get sucked in.
400
What are 3 ways to change the overall density of an object?
Change its mass, volume, shape
400
What on a submarine controls sinking, floating and suspending?
Ballast tanks
500
The deeper you go in a fluid, the more pressure there is. Explain why.
At a deeper level, there is more fluid sitting on you. More fluid means more weight (a force). More force means more pressure since pressure is simply force over area.
500
1. Explain how buoyant force and weight of an object determine whether an object will sink or float. 2. Explain why steel ships are able to float in water even though steel is denser than water.
1. BF>weight---buoyed up/float BF
500
What must the pilot do if he wants the plane to rise higher? Explain how this leads to the plane rising higher.
Increase thrust/more engine power. This moves the plane faster. Which means air is moving faster above the wing, pressure decreases even more above the wing, causing the plane to rise as Lift increases.
500
You are riding in a car on a highway when a large truck speeds by you. Your car is force toward the truck. Which principle is in play here? Explain.
Bernoulli's Principle. Air between car and truck is moving faster, so creates a low pressure zone. High pressure on either side of car and truck so get sucked in.
500
Explain how a tornado works.
Air in the middle of a tornado is moving very fast, creates a low pressure zone. high pressure outside, so everything gets sucked in.