Basis of Unit 8
T/F - An ideal fluid is compressible.
False
As the mass increases, what happens to the density?
It increases
What would make a more ideal fluid?
Honey vs. Ketchup
Honey
What is pressure?
A constant force applied onto an object
Which is the most dense?
A.) M = 7.2kg ; V = 1.9m3
B.) M = 5.5kg ; V = 2.6m3
C.) M = 2.3kg ; V = .34m3
C
What is the unit for Pressure?
Pascals
As the volume increases, what happens to the density?
It decreases
If an object is the same density as water was placed at the bottom of a pool, what would happen?
The object would sit at the bottom until something moved it.
To find gauged pressure in a fluid, what variables need to be multiplied together?
pgh
p = fluid Density
g = Gravity
h = fluid depth (height)
When sprinting, would you apply more pressure to the ground using running shoes or soccer cleats and why?
The soccer cleats because the surface area of the cleats are smaller that the surface area of the sneaker.
What is a fluid?
Anything that takes the shape of it's container.
(Liquids & Gases)
If a sphere with a radius of 3cm had a density of 3kg/cm what would the mass be?
~ 3/113.10 or .027
What is the Buoyant Force Fromula
Fb = mf(g) or Fb = pfVf(g)
Two rectangular blocks of the same mass are placed on a table. One is placed on the long side, making its surface area larger, and another is placed on its shorter side, making its surface area smaller.
Which applies more pressure to the table
The rectangular blocks with a smaller surface area
A single conservative force Fx = (6.0x−12) N (x is in m) acts on a particle moving along the x axis. The potential energy associated with this force is assigned a value of +20 J at x = 0. What is the potential energy at x = 3.0 m?
a. +11 J
b. +29 J
c. +9.0 J
d.−9.0 J
B
How does surface area relate to pressure?
As the surface area increase, the pressure decrease.
The following is provided about two spheres' radius and mass. Which would have a higher density?
Sphere 1 - Radius = R ; Mass = 2M
Sphere 2 - Radius = 2R ; Mass = 4M
Sphere 1 would have a higher density
What is a fluid?
Anything that takes the shape of its container.
(Liquids/Gases)
As your surface area increases, the pressure does what?
Decrease
A swimmer is 2m below the surface of a lake. What is the pressure caused only by the water?
A.) 1960 Pa
B.) 9860 Pa
C.) 1800 Pa
D.) 9800 Pa
D
p(g)
1000kg(9.8)
What is the pressure formula?
p = Fperp/A
Fperp = Perpendicular Force
A = Surface Area
p = Pressure
A balloon filled with gas is compressed. The volume shrinks, but the gas inside is still the same amount. Which is true?
A.) The density decreases because the volume decreases
B.) The density remains the same because the gas remains constant
C.) The density increases because the volume decreases
C
5 fluids are placed into a glass and disperse out. How do you know which one will be at the bottom?
You find the liquid with the highest density
Which applies more pressure to the ground, a person standing or a person laying on the ground?
The person standing
A cube of wood floats in a pond with 3/4 of its volume submerged. What conclusion can we draw about the density between the pond and the wood?
The density of the wood is 3/4 the density of water