Question

1. Please use the equations to support your answers. What and why is the main energy consumption difference for the car driving in city or highway?

2. What is the principle for the flying and how to drive an airplane with high-energy efficiency ? Please use the equations to support your answers.

Answer 1

1)

The main difference is that in city brakes are applied multiple/more times than on the highway.

By observing Driving Aggressiveness:-

For Highway :-

For City:-

We can conclude,

Energy consumption is more efficient on Highway.

2)

Principle of flying:-

There are four forces acting on the airplane all the time during airplane is flying. The four forces are
(1) Lift,

(2) Gravity force or Weight,

(3) Thrust,

(4) Drag.

Lift is produced by a lower pressure created on the upper surface of an airplane's wings compared to the pressure on the wing's lower surfaces,causing the wing to be LIFTED upward. The special shape of the airplane wing (airfoil) is designed so that air flowing over it will have to travel a greater distance and faster resulting in a lower pressure area (see illustration) thus lifting the wing upward. Lift is that force which opposes the force of gravity (or weight)

Lift depends upon (1) shape of the airfoil (2) the angle of attack (3) the area of the surface exposed to the airstream (4) the square of the air speed (5) the air density.

Weight The weight acts vertically downward from the center of gravity (CG) of the airplane.

Drag: is the force which opposes the forward motion of airplane. specifically, drag is a retarding force acting upon a body in motion through a fluid, parallel to the direction of motion of a body. It is the friction of the air as it meets and passes over an airplane and its components. Drag is created by air impact force, skin friction, and displacement of the air.