AER1: Introduction

Question 1

Define aerodynamics

Answer 1

The study of forces and the resulting motion of objects through air.

Question 2

Define Vectors

Answer 2

Show magnitude AND direction, can represent forces and be used to sum a result.

Question 3

What is the difference between speed and velocity

Answer 3

Speed is a scalar quantity , the rate at which an object is moving. Magnitude only.

Velocity is a vector quantity and is the rate and direction at which an object is moving.

Question 4

Define Force and Newtons

Answer 4

Force is a vector quantity; direction of push/pull and magnitude (in Newtons).
1 N is the force required to give 1kg an acceleration of 1 meter per second.

Question 5

Define Static Force

Answer 5

Static Force is a force which acts regardless of the movement of air or aircraft. E.g. Gravity

Question 6

Define Dynamic Force

Answer 6

Dynamic Force is one that causes or is a result of the aircraft’s movement or movement of the air. E.g. Lift/Thrust/Drag.

Question 7

Define Newtons Law One

Answer 7

An object will continue to move through space at a constant velocity until an external force is applied

Question 8

Define Newtons law Two

Answer 8

If a force is applied to an object, it will accelerate at a rate proportional to its mass and the force applied:
F = ma

Question 9

Define Newtons law Three

Answer 9

For every action, there is an equal and opposite reaction

Question 10

Define energy

Answer 10

A body or object has energy when it has the capacity to do work. These are Scalar quantities (Joule). Energy cannot be created or destroyed, only manipulated in its form.

Question 11

Define Kinetic Energy

Answer 11

Energy produced as a result of motion. Proportional to velocity

Question 12

Define Potential energy

Answer 12

Energy that is stored by an object which has the potential for use.

Question 13

Define a gas

Answer 13

A group of molecules that are not bonded together.

Question 14

How is density of gas measured

Answer 14

Measured by the quantity of particles in a given volume or space and is a function of temperature and pressure.

Question 15

What happens to the density of a gas if the pressure increases?

Answer 15

Density will also increase as more gas particles are getting pushed closer together.

Question 16

What happens to the density of a gas if the temperature is increased?

Answer 16

The density will decrease as the particles have more kinetic energy due to the heat and will be repelling each other more.

Question 17

Define Boyle’s Law

Answer 17

Pressure and volume of gas have an inverse relationship, when the temperature remains constant. (Volume increases, Pressure decreases and vice versa)

Question 18

Define Lussac’s Law

Answer 18

When the volume is kept constant, temperature increases and pressure will also increase (and vice versa)

Question 19

What are the four forces on an aircraft in flight?

Answer 19

Lift, Thrust, Weight, Drag

Question 20

Define Lift

Answer 20

Produced by the aircraft’s wing, acts perpendicular to the relative airflow

Question 21

Define weight

Answer 21

Caused by gravity (1G), acts through the centre of gravity of the aircraft towards the earth

Question 22

Define Thrust

Answer 22

Produced by the power plant of the aircraft, acts through the prop/engine in the direction of flight

Question 23

Define drag

Answer 23

Produced by the lifting action of the wing and the shape of the aircraft not producing lift. Acts opposite to the flight path.

Question 24

Define total reaction

Answer 24

The result of all aero - dynamic forces acting on the wing or aerofoil.

Question 25

Define Pressure distribution

Answer 25

The way pressure acts on all surfaces of the aerofoil.