physics Flashcards
Define fluid
substance that deforms(flows) in presence of shear stress & external force.
Define Pressure
force acting upon per unit area of surface.
P=f/a
S.I unit= N/m^2 or Pascal
What is Pressure depth relation
Expression for measure of pressure of any depth below the surface of liquid is given by P= hpg
h=depth below surface of liquid
p=density of liquid
g=acceleration due to gravity
Define Atmospheric Pressure
Pressure exerted due to atmosphere at a place.
N/m^2
What is Pascal’s law and state 3 applications
*When pressure is applied to an enclosed liquid at rest, the pressure increased at every point in liquid by an amount is equal to the pressure applied.
*Hydraulic press
*Hydraulic brakes
*Hydraulic lift
Define archimedes principal & one application
When an object in completely or partially submerged in liquid it experiences a loss in weight which is equal to the the weight of the liquid displaced by the body.
Ships
What is viscous force & viscosity?
Viscous force is an internal for e developed b/w 2 layers of liquid to oppose relative motion b/w the layers.
Viscosity is the property by virtue of which liquid opposes relative motion b/w layers
Define Velocity gradient with formula & S.I unit
change in velocity per unit change in distance b/w liquid layers.
1/s
V.G=dv/dx
What is Newton’s law of viscousity
Viscous force F developed b/w 2 layers of liquid directly proportional to i. velocity gradient ii. surface area of liquid layers
Define Coefficient of viscosity & state its CGS unit
Viscous force developed b/w 2 liquid layers of unit surface for unit velocity gradient.
poise.
Define Poise
coefficient of viscosity which is equal to 1 poise if 1 dyne viscous force is developed b/w the liquid layers of 1 cm^2 area for unit velocity gradient.
