Com·ma
/ˈkämə/
NOUN
1. a punctuation mark (,) indicating a pause between parts of a sentence. It is also used to separate items in a list and to mark the place of thousands in a large numeral.
2. a minute interval or difference of pitch.
Answer:The Wright brothers invented and flew the first airplane in 1903, recognized as "the first sustained and controlled heavier-than-air powered flight". ... Airplanes had a presence in all the major battles of World War II. The first jet aircraft was the German Heinkel He 178 in 1939.
Explanation:
Answer:
A mock-up
Explanation:
It is made of cheap and easy to access parts.
Answer:
The conversion in the real reactor is = 88%
Explanation:
conversion = 98% = 0.98
process rate = 0.03 m^3/s
length of reactor = 3 m
cross sectional area of reactor = 25 dm^2
pulse tracer test results on the reactor :
mean residence time ( tm) = 10 s and variance (∝2) = 65 s^2
note: space time (t) =
t = 
Vo = flow metric flow rate , L = length of reactor , A = cross sectional area of the reactor
therefore (t) = 
= 25 s
since the reaction is in first order
X = 1 - 
= 1 - X
kt = In 
k = In / t
X = 98% = 0.98 (conversion in PFR ) insert the value into the above equation then
K = 0.156 
Calculating Da for a closed vessel
; Da = tk
= 25 * 0.156 = 3.9
calculate Peclet number Per using this equation
0.65 = 
therefore
solving the Non-linear equation above( Per = 1.5 )
Attached is the Remaining part of the solution
Answer:
The process of generation of force by the high speed that pushes the jet engine forward is based on Newton’s 2 law of motion ?
Explanation:
1, Newton’s first law states that, if a body is at rest or moving at a constant speed in a straight line, it will remain at rest or keep moving in a straight line at constant speed unless it is acted upon by a force. This postulate is known as the law of inertia.
2,
Newton’s second law is a quantitative description of the changes that a force can produce on the motion of a body. It states that the time rate of change of the momentum of a body is equal in both magnitude and direction to the force imposed on it. The momentum of a body is equal to the product of its mass and its velocity. Momentum, like velocity, is a vector quantity, having both magnitude and direction. A force applied to a body can change the magnitude of the momentum, or its direction, or both.For a body whose mass m is constant, it can be written in the form F = ma, where F (force) and a (acceleration)
3, Newton’s third law states that when two bodies interact, they apply forces to one another that are equal in magnitude and opposite in direction.The third law is also known as the law of action and reaction. This law is important in analyzing problems of static equilibrium, where all forces are balanced, but it also applies to bodies in uniform or accelerated motion. The forces it describes are real ones, not mere bookkeeping devices. For example, a book resting on a table applies a downward force equal to its weight on the table. According to the third law, the table applies an equal and opposite force to the book.
