Physics Flashcards
oral questions
Define matter
Any substance that occupied space and has mass
Matter may exist in what three states
Solid liquid and gas
Define kinetic energy
Is the energy in motion
Work is the product of what two factors
Force and distance moved
What are the part of a lever
A rigid bar abd a pivot point call the fulcrum
A wheel barrel in an example of what class of leveler
A second class lever
Are all three states of matter affected, by thermal expansion and if so which states is affected
All three states are affected with gasses being affected the most.
What is the british thermal unit
The amount of heat of energy required to change the temperature of 1 pound of water 1 degree fahrenheit
Name the three methods of heat transfer
Conduction, convection and radiation
What term defines the temperature which all molecular motion cease.
Absolut Zero
Can liquids be compress
No,. liquids are generally considered imcompresible
What are the customary units used to express hydraulic or pneumatic pressure in the USA
Pounds per square inch
Describe how pressure is transmitted when pressure is applied in a confined liquid
Pressure is transmitted equal in all directions
What formula expresses the relationship between force, pressure and area
Force equals area times pressure
What is the approximate speed of sound at sea level on a standard day
661 Knots or 340 meters per second
whats is the atmospheric pressure at sea level on a standard day
29.92 inches of mercury or 1013.2 millibars
On a standard day at sea level what is the value of temperature
59 degrees Fahrenheit or 15 degrees Celsius
What are the factors that determined density altitude
temperature and atmospheric pressure
What is the term used to describe the ratio between the amount of moisture actually present in the atmosphere as compared to the amount the air could hold if it were completely saturated.
Relative humidity
What are four principle forces acting on an airplane in flight
Lift, drag, thrust and gravity
what is the term that describe the angle between the relative wind and the chord line of an airfoil
Angle of attack
what are factors that cause an airplane wing to stall
Stall is cause when the angle of attack exceeds a critical value and the airflow separates from the upper surfaces and becomes turbulent.
What are the principal effects that result from lowering the flaps while in flight
Lift increases drag increases and stall speed decreases
What is the function of wing mounted vortex generratos
They dealy or keep the airflow from separating from the upper surface of a wing during high speed flight .
How does blade flapping help to compensate for dissymmetry of lift in helicopter main rotor systems
Flapping increases the angle of attack and lift on the retreating blade and decreases the angle of attack and lift and the advancing blade.
How does the airflow through the main rotor of a helicopter change during the transition from normal flight to autorotation
During normal flight the air moves downward and during autorotation the air moves upward
what is friction
The opposition to relative motion between two objects in contact with each other
