Aeroscience Flashcards
What are newtons laws
1st - every object continues in its state of rest or of uniform motion in a straight line, unless acted upon by an external force.
2nd - f = ma
3rd - for every action theres an equal and opposite reaction
Explain inertia
The tendency of an object to continue moving at a certain velocity (or to remain at rest with zero velocity.)
Difference between weight and mass
Weight - the force that gravity exerts on an object
Mass - the amount of matter in an object
What is momentum
The momentum of an on just refers to the difficulty of stopping a moving object or of changing its direction of travel.
P=mv
Differentiate between centripetal and centrifugal force.
Centripetal - aircraft turns in. CPF = m x v^2/r or Wv^2/gr
Centrifugal - aircraft turns out
What are the factors affecting CPF and rate of turn.
CPF = wv^2/gr
Where w = weight (weight = mass x g)
G = gravity
R = radius
Rate of turn depends on the ratio v/r. (Velocity / radius)
Describe the moment of a force, and the moment of a couple
Force - Turning force about a pivot. Perpendicular distance x force
Couple = two equal but opposite parallel fkrces
Describe the conditions required for translational equilibrium and for rotational equilibrium
Translational - Object at rest or at constant velocity. Sum of all forces acting on the object is zero.
Rotational - no angular acceleration and sum of all moments zero. Object is rotating at a constant rate or is stationary.
What is constant rpm rotational equilibrium?
Aircraft with a propeller that has a constant rate of rotation and to remain constant the torque produced by the engine and transmitted through the hub of the propellor is balanced by drag.
What is CoG
The point at which weight is evenly dispersed and all sides are in balance.
Weight acts through CoG
What is the formula for work power and energy
W =fd
P = w/t
Ek = 1/2mv^2 Pe = mgh
What is kinetic energy in comparison to potential energy
Kinetic - energy due to motion.
Potential energy - energy of position.
