PoF Flashcards
Units of Distance
1NM = 1852M
1M = 3.28ft
1KM = 1000m
Units of Vertical speed
1m/s to 196.8fpm
Units of Horizontal Speed
M/s = 0.5144 x knots
Approximate Conversion factor -> Halve the number of its to find m/s
Units of Acceleration
Acceleration is the change in velocity
1kg force = 9.81N
Mass x Acceleration = Force
Momentum
Can never be lost -> it’s always in exchange with other masses
Mass(kg) x Velocity(m/s) = Momentum
What is Energy?
Energy is the capacity to do work on something. It is ‘conserved’ meaning it cannot be created or destroyed.
What is kinetic energy?
The energy possessed by a mass in motion.
Kinetic energy can be converted into other sorts of energy.
What happens to the energy when the velocity has doubled?
The energy increases 4x.
What’s the formula for kinetic energy
1/2 x mv^2
What is pressure energy?
It is contained in billions of molecules in a gas.
What is work?
It is energy converted from one to the other.
What is the formula for work?
Force(N) x Distance(m) = Work
What is power? What is the SI unit of power?
Power is the rate of doing work
The SI unit of power is watt(w)
What are the equations of power?
Power = work / time
Or
(Force x Distance) / Time
What is Newtons 1st Law?
A body will remain at rest or in uniform motion unless acted upon by external force e.g throwing a hammer at 5m/s.
What is Newtons 2nd law?
The acceleration of a body in a straight line is proportional to the applied force and inversely proportional to the mass of the body
e.g pushing two balls with the same force but different sizes.
What is Newtons 3rd Law?
To each and every action there is an equal opposite reaction.
e.g when a ball is pushed and hits another ball, the energy is transferred onto the other ball making the ball move along.
What are the implications of newtons laws?
- Thrust force is created with accelerating molecules
- Weight acts downwards.
- In level flight if an aircraft has a weight force of 20,000N the lift force is 20,000N.
What is density proportional and inversely proportional to?
It’s proportional to pressure
It’s inversely proportional to temperature.
What’s dynamic pressure and what is the formula for it?
Pressure in the air that tributes to movement (goes in all direction)
1/2 x p x (v^2)
What are the errors of different airspeed?
Instrument -> Indicated Airspeed -> Position error
Pressure -> Calibrated Airspeed -> Compressibility error
Compressed -> Equivalent Airspeed -> Density error
What’s the equation for True Airspeed (TAS)?
TAS = EAS x sqrt(1.225 (Po) /modified density (P) )
What is the formula for Equivalent Airspeed (EAS)?
TAS = EAS x sqrt ( modified density (P) / 1.225 (Po) )
Which property of air is responsible for frictional forces (stickiness)
Viscocity