Day One Tech Flashcards
Scalar
a quantity that represents only magnitude, e.g., time, temperature, or volume
Vector
is a quantity that represents
magnitude and direction
Displacement
) is the distance and direction of a body’s movement
Velocity
) is the speed and direction of a body’s motion, the rate of
change of position
Speed
is a scalar equal to the
magnitude of the velocity vector
Acceleration
) is the rate and direction of a body’s change of velocity (gravity accelerates bodies toward the center of the earth at 32.174 ft/s2 )
Force
is a push or pull exerted on a body (1,000 lbs of thrust pushes a jet through the sky)
Mass
) is the quantity of molecular material that
comprises an object.
Volume
is the amount of space occupied by an object
Denisty
is mass per unit volume. It is expressed:
volume
mass
ρ = m/v
Weight
) is the force with which a mass is attracted toward the center of the earth by gravity.
Force
is mass times acceleration
Moment
is created when a force is applied at some distance from an axis or fulcrum,
and tends to produce rotation about that point. A moment is a vector quantity equal to a force
(F) times the distance (d) from the point of rotation that is perpendicular to the force (Figure
1-1-2). This perpendicular distance is called the moment arm.
Work
is done when a force acts on a body and moves
it. It is a scalar quantity equal to the force (F) times the
distance of displacement (s)
W = F * s
Power
is the rate of doing work or work done per unit
of time.
P = W/t
Energy
y is a scalar measure of a body’s capacity to do work. There are two types of energy:
potential energy and kinetic energy. Energy cannot be created or destroyed, but may be
transformed from one form to another. This principle is called conservation of energy. The
equation for total energy is:
TE = PE+KE
Potential Energy
is the ability of a body to do work because of its position or state of
being. It is a function of mass (m), gravity (g), and height (h):
PE = weight * height = mgh
Kinetic Energy
) is the ability of a body to do work because of its motion. It is a function of
mass (m) and velocity (V):
KE = 1/2mV^2
Work
may be performed on a body to change its position and give it potential energy or work
may give the body motion so that it has kinetic energy. Under ideal conditions, potential
energy may be completely converted to kinetic energy, and vice versa. The kinetic energy of a
glider in forward flight is converted into potential energy in a climb. As the glider’s velocity (KE)
diminishes, its altitude (PE) increases.
Newton’s First Law
The Law of Equilibrium:
“A body at rest tends to remain at rest and a body in motion tends to remain in
motion in a straight line at a constant velocity unless acted upon by some
unbalanced force.”
Equilibrium Flight
is the absence of acceleration, either linear or angular.
ar. Equilibrium flight exists when the
sum of all forces and the sum of all moments around the center of gravity are equal to zero.
An airplane in straight and level flight at a constant velocity is acted upon by four forces: thrust,
drag, lift and weight. When these forces exactly cancel each other out, the airplane is in
equilibrium
Trimmed Flight
exists when the sum of all moments around the center of gravity is equal to
zero. In trimmed flight, the sum of the forces may not be equal to zero. For example, an
airplane in a constant rate, constant angle of bank turn is in trimmed, but not equilibrium, flight.
An airplane in equilibrium flight, however, is always in trimmed flight
Newton’s Second Law
The law of accelration
An unbalanced force (F) acting on a body
produces an 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
a = F/m
Newton’s Third Law
The law of interaction
For every action, there is an equal and opposite reaction.
Hot gases exhausted rearward produce a thrust force acting forward
