Show:
Fluids
Pressure
Pressure Exerted By Fluids
Mechanisms Related to Variations in Pressure of Fluids
Surprise
100
True or false: air, dish soap, tar, toothpaste, mercury and salt are all fluids.
False. Salt is not a fluid.
100
Which two variables affect pressure?
Surface area and force
100
In a compressible fluid (like air), pressure depends on the number of _____________.
Collisions
100
True or false: Pressure applied to the surface of a fluid inside a closed container gets distributed to only parts of the fluid.
False. Pressure gets uniformly distributed to every part of the fluid.
100
Pressure is equal to surface area divided by force. True or false?
False. P = F/A
200
What two characteristics do fluids possess?
1. The capacity to flow and 2. assume the form of the container into which it has been poured.
200
What is pressure? And what is the unit of measurement?
The result of a force applied in a perpendicular fashion to a surface. It is measured in pascals (Pa).
200
In an incompressible fluid (like water), the pressure exerted depends on what two things?
1. The depth of the object in the water and 2. the density of the fluid.
200
Why does whipped cream from a compressed can quickly escape when the seal is cracked?
A fluid naturally moves from a zone of high pressure toward a zone of low pressure. The pressure outside the can is less therefore the fluid moves out.
200
Why might someone say that a high heeled shoe exerts more pressure on the ground than the foot of an elephant?
The shoe has less surface area than the elephant foot and therefore applies more pressure.
300
A fluid whose volume can be changed. CO2 gas is an example.
A compressible fluid.
300
Why is the tip of a needle for sewing so little? (Use what you know about pressure).
It has a tiny surface area which creates a lot of pressure. This pressure allows it to penetrate into materials.
300
What is an example of a tool used to measure an incompressible fluid?
U-shaped manometer, depth gage, a tonometer
300
What does high blood pressure mean?
When your heart beats, it contracts and pushes blood through the arteries to the rest of the body. This force creates pressure on the arteries. When there is cholesterol build up in the arteries, the heart has to work harder to pump the blood to the rest of your body and therefore the pressure against the arteries increases.
300
What is the pressure exerted by a 2 kg (20N) box placed on a table? The increments of the box are 0.1m by 2m.
100 Newtons (N)
400
What do the particles in an incompressible fluid look like? What is one example?
Particles are close together (less close than in solids) and are held together by forces of attraction that are relatively weak. Particles slide over each other to take on the form of the container.
400
Who exerts more pressure on the ground: a mouse or an elephant? Why? (Must use the right vocabulary to get points).
The elephant because it has more mass which means more FORCE. More force = more pressure.
400
Can a balloon filled with helium rise above the atmosphere? Why or why not?
No, it would eventually burst because the volume of the balloon would increase as the atmospheric pressure decreased.
400
Give an example (that we saw in class) of when a transfer of pressure in a fluid can increase the force involved.
Hydraulic mechanisms. Applying a weak downward force to a small piston that transfers the pressure to a large piston (with more force). This mechanism allows heavy objects (such as cars) to be lifted.
400
In class we talked about two different types of "force". What were they?
1. an action that modifies the movement of an object and 2. gravity (greater mass=greater force)
500
Using the molecular model, explain why gases are compressible and liquids or solids are not.
Gas particles are very far apart, so they have room to get closer together when they are compressed, whereas particles in liquids and solids are very close together and with no room to get closer when they are compressed.
500
What force is required for a device to exert a pressure of 250 Pa on a surface of 1.5 m2?
375 Newtons (N)
500
When Mr. Tremblay created a vacuum in the jar, what happened to the balloon inside the jar? Why did this happen?
The balloon expanded because there were no more air particles left in the jar, therefore the pressure decreased significantly. There was therefore less pressure on the balloon and it expanded.
500
Explain why blood circulates naturally from arteries to veins.
Because the pressure in arteries is higher than that in veins and fluids naturally flow from a high pressure area to a low pressure area.
500
Which team won the Grey Cup in 2013 and where was the game held?
Saskatchewan ROUGHRIDERS won in REGINA, SASKATCHEWAN!!! :D