/*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none} Q12Q During a routine flight in 1956,... [FREE SOLUTION] | 91Ó°ÊÓ

91Ó°ÊÓ

During a routine flight in 1956, test pilot Tom Attridge put his jet fighter into a20°dive for a test of the aircraft’s 20 mmmachine cannons. While traveling faster than sound at 4000 m altitude, he shot a burst of rounds. Then, after allowing the cannons to cool, he shot another burst at 2000 m; his speed was then344 m/s, the speed of the rounds relative to him was 730 m/s, and he was still in a dive. Almost immediately the canopy around him was shredded and his right air intake was damaged. With little flying capability left, the jet crashed into a wooded area, but Attridge managed to escape the resulting explosion. Explain what apparently happened just after the second burst of cannon rounds. (Attridge has been the only pilot who has managed to shoot himself down.)

Short Answer

Expert verified

After the second burst of cannon rounds, the actual velocity of the cannon rounds became less than the speed of the plane so the plane hits the cannon before the explosion happens.

Step by step solution

01

The given data

  1. A jet fighter puts a 20°dive for a test of 20 mm machine cannons.
  2. With a speed greater than the speed of light at 4000 m altitude, he shot the burst.
  3. After cooling, he shot the next burst at 2000m altitude, his speed was 344 m/s.
  4. Speed of the rounds relative to him was 730 m/s.
  5. Then immediately, the canopy was shredded and his right air intake got damaged.
02

Understanding the concept of the drag force

For decreasing altitude, the density of the air increases accordingly. Now, using the concept of drag force, and the given value of the speed of the cannon rounds, we can get the reason for the hit with the plane before the explosion happens.

Formula:

The drag equation relating the force to speed and density,

FD=CDApV22 (1)

whereFD is the drag force,

CDis the drag coefficient,

A is the reference area,

pis the density of the fluid,

Vis the flow velocity relative to the object.

03

Calculation of the state of the cannon rounds after the second burst

Initially when Tom Attridge was at 4000 m altitude shot for the first time but after that, he was at 2000 m altitude in the 2nd case. At this altitude, the air is denser than at the altitude 4000 m. As the plane was flying at supersonic speed, the drag force due to the air on the bullet is greater considering equation (1). Thus, within moments the actual velocity of bullets became less than the plane and the plane hit those bullets therefore the explosion happens.

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Over 30 million students worldwide already upgrade their learning with 91Ó°ÊÓ!

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

An initially stationary box of sand is to be pulled across a floor by means of a cable in which the tension should not exceed 1100N. The coefficient of static friction between the box and the floor is 0.35. (a) What should be the angle between the cable and the horizontal in order to pull the greatest possible amount of sand, and (b) what is the weight of the sand and box in that situation?

A 3.5kgblock is pushed along a horizontal floor by a force of magnitude 15Nat an angle with the horizontal (Fig. 6-19). The coefficient of kinetic friction between the block and the floor is 0.25. Calculate the magnitudes of (a) the frictional force on the block from the floor and (b) the block’s acceleration.

Assume Eq. 6-14 gives the drag force on a pilot plus ejection seat just after they are ejected from a plane traveling horizontally at1300km/h. Assume also that the mass of the seat is equal to the mass of the pilot and that the drag coefficient is that of a sky diver. Making a reasonable guess of the pilot’s mass and using the appropriatevtvalue from Table 6-1, estimate the magnitudes of (a) the drag force on the pilot seatand (b) their horizontal deceleration (in terms of g), both just after ejection. (The result of (a) should indicate an engineering requirement: The seat must include a protective barrier to deflect the initial wind blast away from the pilot’s head)

Calculate the magnitude of the drag force on a missile 53 cmin diameter cruising at 250 m/sat low altitude, where the density of air is1.2kg/m3. AssumeC=0.75.

A student, crazed by final exams, uses a force of magnitude 80Nand angleθ=70°to push a 5.0 kg block across the ceiling of his room (Fig. 6-52). If the coefficient of kinetic friction between the block and the ceiling is 0.40, what is the magnitude of the block’s acceleration?

See all solutions

Recommended explanations on Physics Textbooks

View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.