Fluid Mechanics & Hydraulics
According to _______________, the pressure of a fluid decreases at points where the velocity of the fluid increases.
Bernoulli's principle
What is the measure of the kinetic energy of the molecules of any substance?
Temperature.
What is the definition of the aspect ratio of a wing?
ratio of the wingspan to the mean chord.
What is Newton's first law of motion?
Objects at rest tend to remain at rest and objects in motion tend to remain in motion unless acted on by an external force.
What is the purpose of stall strips?
The purpose of stall strips is to ensure that the wing root areas stall first.
If the temperature of a confined liquid is held constant and its pressure is tripled, the volume will _________________.
remain the same. Liquids are incompressible
What are The three methods of heat transfer?
conduction, convection, and radiation
How is Aerodynamic lift produced?
Aerodynamic lift is produced by positive air pressure below the wing and negative air pressure above the wing, along with downward air deflection
What are the three necessary factors to determine power in physics?
force exerted, distance moved, and time required.
What stability does an Aircraft wing dihedral provide?
lateral stability
The boiling point of a given liquid varies _________ with pressure
directly
What is the temperature to which humid air must be cooled at constant pressure to become saturated?
dewpoint.
What does a high aspect ratio wing have over a low aspect ratio wing, in terms of stall speed?
A wing with a high aspect ratio will have a low stall speed compared to a low aspect ratio wing.
To lift a 60-pound weight using a block and tackle with four supporting ropes, What is the force that must be applied to the pull rope?
15 pounds
What is the desired effect of using winglets on an aircraft's wingtips?
To increase the lift-to-drag ratio.
A double-acting actuating cylinder in a 3,000 psi system with an effective area of two square inches on the retracting side will produce _________________ when retracting.
6,000 pounds of force
What is the actual amount of water vapor in a mixture of air and water?
absolute humidity
What are the primary flight controls?
Ailerons, Rudders & Elevators
What is the amount of work required to lower a 120-pound weight from a 3-foot table to the floor?
360 foot-pounds.
What are the three principal classifications of main rotor systems in helicopters?
fully articulated, semi-rigid, and rigid.
If the fluid pressure is 800 PSI in a 1/2-inch line supplying an actuating cylinder with a piston area of 10 square inches, the force exerted on the piston will be ________________.
8,000 pounds
If both the volume and the absolute temperature of a confined gas are doubled, the pressure will __________.
not change
If a stall strip is missing from a wing, what will be the result?
asymmetrical lateral control at or near stall angles of attack.
How much force is required to roll a 120-pound barrel up a 9-foot inclined plane to a height of 3 feet?
40 pounds
What needs to be raised for the blade angle of all rotor blades in a helicopter to increase uniformly to allow a vertical takeoff?
collective pitch control lever