T-34 Questions - Basic Properties of Physics Flashcards
How does vector quantity differ from scalar quantity?
A scalar is a quantity that represents only magnitude. A vector is a quantity that represents magnitude and direction.
Define mass
Mass is the quantity of meoecular material that comprise an object
Define weight
Weight is the force at which a mass is attracted toward the center of the earth by gravity
Define air density
The density of the air is the mass of air per unit of volume
How are force and moment related?
A force is a push or pull exerted on a body. It tends to produce motion along a line. A moment is a tendency to produce motion about a point or axis. It is created by applying force to a lever arm to induce rotational motion about an axis.
Define work. How is it calculated?
Work is done when a force acts on a body and moves it. W=F x s
Define power
Power is the rate of doing work
Define energy. What is the equation for total energy?
Energy is the ability to do work. TE = PE + KE
Define potential energy (PE)
Potential Energy is the ability of a body to do work because of its position or state of being.
Define kinetic energy (KE)
Kinetic Energy is the ability of a body to do work because of its motion. KE = 1/2 mV^2
State Newton’s First Law of Motion
Newton’s First Law of Motion is the Law of Equilibrium. A body at rest tends to stay at rest and a body in motion tends to stay in motion in a straight line at a constant velocity unless acted upon by some unbalanced force.
Under what conditions can both an airplane traveling at a constant speed and direction and an airplane parked on the flight line be in equilibrium?
An airplane traveling at a constant speed and direction, and and airplane parked on the flight line are in equilibrium if the sum of the forces and moments about the CG equal zero.
What is the difference between trimmed flight and equilibrium flight?
Trimmed flight exists when the sum of the moments acting about the CG equals zero, where equilibrium flight exists when the sum of the forces AND the moments about the CG equal zero.
State Newton’s Second Law of Motion.
Newton’s Second Law of Motion is the Law of Acceleration: An unbalanced force (F) acting on a body produces and acceleration (a) in the direction of the force that is directly proportional to the force and inversely proportional to the mass (m) of the body. An example is an aircraft in a turn.
State Newton’s Third Law of Motion.
Newton’s Third Law of Motion is the Law of Interaction: For every action, there is an equal and opposite reaction.
Define static pressure. What change in atmospheric static pressure (PS) occurs with an increase in altitude?
Static Pressure is the weight and volume of air over a given area. Static pressure decreases with an increase in altitude.
What change in air density occurs with an increase in altitude?
Air density decreases with and increase in altitude.
Define air temperature.
Air temperature is a measure of the average kinetic energy of air particles.
What change in air temperature occurs in the standard atmosphere from sea level through 66,000 feet?
Air temperature decrease by 2C / 1,000’ until approximately 36,000’ and isothermic layer w/a constant temp of about -56.6C exists aprox FL36-FL660
What change in air density occurs with an increase in humidity?
Air density decreases with an increase in humidity.
Define air viscosity. What change in air viscosity occurs with an increase in temperature?
Air viscosity is a measure of air’s resistance to flow and shearing.
What is the primary factor affecting the speed of sound in air?
The primary factor in determining speed of sound in air is temperature.
What are the sea level conditions in the standard atmosphere?
Static Pressure: 29.92 inHg / 1013.25 mbar
Temperature: 59F / 15C
Avg. Lapse Rate: 3.57F per 1,000’ / 2C per 1,000’
Local Speed of Sound: 66.7 knots / 340.4m/s
State the General Gas Law. What is the relationship between temperature, pressure, and density according to the General Gas Law?
P=pRT Given a constant pressure, density will decrease with an increase in temperature.
