chapter 3

Question 1

what is newton’s law of motion govern ?

Answer 1

the conservation of momentum

Question 2

what is Bernoulli’s equation derived from?

Answer 2

the law of conservation of energy

Question 3

how does lift occur? explain

Answer 3

when a flow of gas is turned by a solid object. The flow is turned in one direction and the lift is generated in the opposite direction

Question 4

because air is a gas and the molecules are free to move about, can any sold object deflect a flow?

Answer 4

yes

Question 5

What are some components of generating lift?

Answer 5

momentum, conserving the mass, and energy in the flow.

Question 6

Define Euler equation?

Who is named after?

Answer 6

The simultaneous conservation of mass, momentum, and energy of a fluid while ignoring the effects of viscosity.

Leonard Euler

Question 7

True or false. lift is generated by a force field through a gravitational force or electromagnetic field.

Answer 7

False. Lift is a mechanical force. In order for lift to be generated the solid body must be in contact with the fluid (liquid or gas); no fluid, no lift. Without air, there is no lift generated by the wings of an aircraft.

Question 8

Is lift generated by the difference in velocity between the solid object and the fluid?

Answer 8

yes

Question 9

True or False: In relation to lift it makes no difference weather the object moved through a static fluid, or the fluid moves past a static object

Answer 9

true

Question 10

lift act ____ to the fluid motion while drag acts in the direction ____ to the motion

Answer 10

perpendicular

opposed

Question 11

what does the lift equation take into account?

Answer 11

the dependence of life on the square of the velocity, the surface area, the shape of the object, inclination of the object to the flow, and the properties of the air.

Question 12

What is newton’s first law?

Answer 12

every object persists in its state of rest or uniform motion in a straight line unless it is compelled to change that state by forces impressed on it.

Question 13

Newton’s second law

Answer 13

force is equal to the change in momentum per change in time. For a constant mass, force equals mass time acceleration

Question 14

When a body is acted upon a constant force, it resulting acceleration in ___ proportional to the mass of the body and is ___proportional to the applied force.

Answer 14

inversely

directly

Question 15

What does Newton’s 2nd law cover?

Answer 15

both changes in direction and speed, including starting up from rest (positive acceleration) and coming to a stop (negative acceleration, or deceleration).

Question 16

Newton’s third law?

Answer 16

For every action there is an equal and opposite reaction

Question 17

In relation to composition of the atmosphere which exerts a mixture of gasses that are governed by the laws of fluid motion. When flowing, each particle’s ___ and ____ are variable, and the path they take is called ______

Answer 17

velocity
direction
stream line

Question 18

How do you form a stream tube?

Answer 18

multiple streamlines flowing adjacent to each other

Question 19

What is a stream tube?

Answer 19

is a closed system within which mass is conserved (neither created or destroyed., but can be transformed from one type to another

Question 20

The mass of air entering the stream tube in a given unit of time exactly equals the mass of air exiting, much like water flowing through a garden hose. How would you find the mass flow?

Answer 20

Mass flow (Q)in slugs per second = multiple cross sectional area of the stream tube (A) by the velocity (v) and the density of the gas (p) such that Q=pAv

Question 21

what is the mass continuity equation used for?

Answer 21

used to explain variations in airflow velocity through varying cross-sectional areas.

Question 22

What is ignored for subsonic flow?

Answer 22

the effects of compressibility are ignored since subsonic flow is incompressible.

Question 23

What happens with incompressible flow?

Answer 23

the density of a fluid is constant and will not change from one location to another.