Physics----Fuids

Fluid.....what's mean by fuids?
Fluids is a material which can flow.First of all,3 states of matter are solids,liquids and gases.From these 3 states of matter,liquids and gases are fluid because they can flow....

MASS DENSITY

equation on mass density
p=m/v the unit is kg/m3(m cubic)

p=mass density , m=mass, v=volume

to use this eq, the eq must related to what types of fluids.
e.g, if the question talk about oil, so the p,m and v must be the p, m and v for the oil

SPECIFIC GRAVITY

equation for s.g

s.g=p of substance/p of water(1000) there is no unit for s.g

PRESSURE

Pressure applied on an immersed object is perpendicular at any point of the object.

eq for pressure P=F/A unit is N/m2(m square) / Pa(Pascal)

P=pressure, F=force (N)/sometmes =W=mg(N)
A=area of the object which make contact with the surface.

PRESSURE WITH DEPTH

P2>P1.......P2 is a pressure under the object while P1 is pressure above the object...P2 must be greater than P1 because P2 must support the object's weight

eq for pressure with depth
P2=P1 + pgh

expand the eq
F2/A2=F2/A2 + pgh

PRESSURE GAUGES

P2-P1=pgh

P2 is the absolute pressure

PASCAL'S PRINCIPLE

As we know P2=P1 + pgh

pascal's principle usually we usd when there is an input piston and output piston.input piston is smaller than output piston.we can conclude that,input piston is P1 and output piston is P2...

when the 2 pistons at the same level we use eq of P2=P1(neglect any height)
in different level we use P2=P1 + pgh

ARCHIMEDES PRINCIPLE

eq Fb(buoyant force)=Wfluid(fluid displaces by object)

to do this kind of question,I suggest to draw a free body diagram.When you draw it,you can see clearly.After draw free body diagram,write the eq based on the diagram and make it = 0.


That's all for this fluids chapter...anything contact me on syuhada_muttaqinah@yahoo.com(my email and ym)