Table 1: Fourth Generation Fighter Jet General Statistics

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18 Νοε 2013 (πριν από 4 χρόνια και 6 μήνες)

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In 1903, the Wright brothers
shocked the world with their demonstration of powered flight
. In a
little more than a century planes have come a long way. The planes driving aerospace
technology are milit
ary aircraft. There have been 4

basic generations of

fighter jets.

We are
just
now
entering the beginning of the fifth generation.
It is a very exciting time.

Ta
ble 1: Fourth Generation Fighter Jet General Statistics

*
The F
-
22 Raptor is a 5
th

generation figh
ter jet.

Table

2
:
Coefficient of Frictions

Material 1

Material 2

Coefficient of Kinetic
friction

Coefficient of Static
Friction

Rubber

Asphalt (wet)

.40

.45

Rubber

Asphalt (dry)

.70

.8

Rubber

Concrete (wet)

.50

.55

Rubber

Concrete (dry)

.75

.85

Rubb
er

Ice

.15

.15

1)
An F
-
22 is cruising at a constant velocity of Mac
h 1.2. This is an amazing feat
because it is
the only fighter in the world that can break the sound barrier without using afterburners

but does
require the full amount of thrust the pla
ne can provide
. What is the drag force (air friction)
acting on the F
-
22?

What must be the lifting force provided by the wings?

2)
A Sukhoi Su
-
27 is in a vertical climb. What is the acceleration of the aircraft? How quickly
can it gain an altitude of
1 mile (1.6 km) if it started from rest (well not really rest, but its vertical
velocity was 0 m/s meaning it was flying horizontally and pulled up hard)
?

3)
An F/A
-
18F is taking off from Edwards Air Force base. In order to take off it needs to
achieve a

speed of 266 km/hr.
Ignoring air friction, what is the minimum amount of runway

does the aircraft need to take off?

4)
An F
-
4EJ Kai’s wheels are malfunctioning and are not able to rotate so when it makes its
emergency landing the wheels skid on the dry

asphalt runway.
The pilot cuts the engines and
touches down with a velocity of 230 km/hr. If friction was the only braking force on the plane
how much runway does the plane need to stop

(this would probably obliterate the landing gear
and is a pretty un
reasonable question to think that the rubber on the tires would last)
?

5) In a really bizarre incident, a Saab JAS 39 Gripen is pulling by a strong yet massless rope a
2500 kg

glider. What is the

tension in the cable? Assume

that neither aircraft experi
ence any
drag.

Fighter

Country

Cost (Millions US\$)

Mass (Kg)

Thrust (kN)

Mirage 2000

France

23

13800

95

Saab JAS 39 Gripen

Sweden

47

8720

54

Sukhoi Su
-
27

Russia

35

23000

245.6

F/A
-
18F Hornet

US

59

21320

124

Chengdu J
-
10

China

--

15230

89

F
-
4EJ Kai

Japan

2.4

18825

159.2

F
-
22 Raptor*

US

120

25107

311.4

Mach Number

is a way of measuring speed. Mach 1 is the speed of sound, mach 2 is twice the
speed of sound, etc. The speed of sound is approximately 340 m/s at standard temperature and
pressure.