Mr mcintyre Flashcards
what is the density equation
density = mass
————
volume
how to determine the density of a liquid
-place a container of a given volume on a scale and find its mass
-fill the container with the liquid and find the new mass
- minus the mass of container from mass of container + liquid
-mass / volume = density!
what is upthrust
upward force applied to an object by the fluid its immersed in
what is Archimedes principle
upthrust = weight of fluid displaced
what’s the equation for upthrust
U(f) = ρ(f) x V(f) x g (f) = of fluid
v = volume
U = upthrust
U(f) = ρ(f) x 3/4πr^3 x g
how to prove an object is floating due to Archimedes principle
- U(f) = w(o)
- ρ(f) x V(f) x g = ρ(o) x V(o) x g
- ρ(f) x V(f) = ρ(o) x V(o)
U = upthrust g = gravity
ρ = density (f) = of fluid
V = volume (o) = of object
what does it mean if an object is floating
its density will be less than that of the fluid but its volume will be greater
if an object is just submerged what does this mean using Archimedes principle
ρ(f) = ρ(o) or ρ(f) x V x g = ρ(o) x v x g
the density of the fluid and object are the same
what is laminar flow
flow in one direction with parallel and constant streamlines
what is turbulent flow
streamlines cross and eddy currents are created, they are constantly changing
when does laminar flow occur
the rate of flow is BELOW a critical value
when does turbulent flow occur
the rate of flow is ABOVE a critical value
or
an object moving through a liquid
what is viscosity
the internal friction between layers of a liquid which resists the flow
what is stokes law
F = 6πηrv
F = drag
η = viscosity coefficient
r = radius of ball bearing
v = velocity of ball bearing
what are the requirements of stokes law
object must be solid smooth and spherical , object must be uniform density , object must be >0.001 compared to fluid molecules , must be laminar flow , fluid must be homogenous
What is Hooke’s law
Force =hooke’s constant x change in length
What does hooke’s law show
That the change in length is directly proportional to the force applied until it reaches the limit of proportionality
What does the area under a force, extension graph equal
Work done
What is stress
Force per unit of cross sectional area
What is the equation for stress
Force
—————————-
Cross sectional area
What is tensile stress
Stress of stretching something
What is compressive stress
The stress caused by pushing things together
What is the equation for strain
Change in length
————————
Original length
What are the components on a stress strain curve
From point of occurrence
- proportional limit
- Elastic limit
- Yield point
- ultimate strength
- rupture strength
