The document discusses the center of pressure and its importance in engineering. It addresses: 1) The relationship between (hp-h(dash)) and (h) and how they relate at different angles Θ. 2) Why the center of pressure is important for engineers, as it allows them to evenly balance lift on aircraft. 3) The difference between the center of pressure and center of gravity - the center of pressure is the point where lifting and drag forces act on a fluid, while the center of gravity is one of the forces that must be considered.

1. Discussion 6.4
Discussionby ahmad jalal hasan
1-draw the relation between (hp-h(dash)) and (h).
2-discuss the relations above and the result of calculating.
When the eualsto 𝛳 = 0 hppara,ℎ 𝑝 𝑡ℎ
− ℎ−
,h are all
equal, so we can observe that this case on th e plot will
seem to be like a vertical line because theres no varity
between values of the all (h) ,this for y axis , but for y axis
as it should be because the (h)s are equal so if subtract
them thuer result will be zero ,so we wont have values as
it shoul be , when the ϴ=90 the relationbetween values
of hpprac-h- and h proportional as it shown on the plot as a
curve line not like first case,, but our last case is when
ϴ=30 the relation here in the first two pointsis inversely
proportionaland in the second and above is directly
propotionalas it seems on the plot.

2. 3-Why is the centre of pressure important?
The center of pressure is the location where the forces of
lifting force and drag forces are exerted on the fluid . It is
very important for engineers to know the center of
pressure because it allowsthem for example to evenly
balancethe lift on aircraft and planes.
4- What is the differencebetweenCentre of pressure and
Centre of gravity?
the place where the resultant vector of all the forces
acting and exerting on the body can be considered to act.
inside or outside a body, that is The center of pressure is
that point,but the center of gravity is one of the forces
that has to be taken into account and should be
considered.
5- why centre of gravity is above the centre of pressure?
If we could say this questionmore clearly "Why is
the centre of pressure below the centre of gravity for a
vertically immersed body in a fluid" the concept is If the
centre of lifting of an object which immersed in a liquidis
above the centre of gravity then the equilibriumshould be
steady and the body will retain to its own orientation.

3. 6-What are the practicalapplication and uses of Centre of
pressure?
One of the very important application is for pitch stability
of an airplaneand flying machines. This is stabilityto the
nose up, nose down Direction in the airoplane.Thisis used
when you design for example a paper airplanes.inthe
airoplanethe locationof the tail and the nose will
represent the center of gravity while the wings are
the center of pressure .
Answers by Muhammed Fuad Rashid
Discussion
Q1