Book answer wrong? Work = Fd question. Space Shuttle entry

In summary, the space shuttle has 8.45 x 10(to the power12) joules of energy transfer over an 8000km flight path, resulting in a force of 1.06 x 10 (to the power nine) Newtons applied by the atmosphere. However, the book's calculation appears to be off by 3 orders of magnitude. The correct calculation would use a distance of 8000 x 10 (to the power 3) resulting in a force of 1.06 x 10 (to the power 6) Newtons. The length of the flight path is necessary for the shuttle to slow down and land safely on Earth.
  • #1
Barclay
208
1

Homework Statement


The space shuttle has 8.45 x 10(to the power12) joules of energy transfer over an 8000km flight path. What force is applied by the atmosphere?

Homework Equations


The book answer is 1.06 x 10 (to the power nine) Newtons.

I think the book answer is wrong. They've shown the calculation as 8.45 x 10(to the power12) / 8 x 10 (to the power 3).

I think the mistake is that they should have used the value 8 x 10 (to the power 3)

The Attempt at a Solution


[/B]
Work = Force x distance

Force = 8.45 x 10(to the power12) / 8000 x 10 (to the power 3).

Force = 1056250 N = 1.06 x 10 (to the power 6)

Please advise. This is High School physics
 
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  • #2
Yes, they appear to be off by 3 orders of magnitude.

By the way, you can use the x2 symbol on the toolbar to get exponents: 103.
 
  • #3
DrClaude said:
Yes, they appear to be off by 3 orders of magnitude.
By the way, you can use the x2 symbol on the toolbar to get exponents: 103.

Thanks ... so my answer Force = = 1.06 x 106 is correct. I was thinking does the shuttle really have a flight path of 8000km as the question says? The distance from atmosphere to Earths surface is much less isn't it ?? Had a quick look on internet and looks like 400 km
 
  • #4
Barclay said:
Thanks ... so my answer Force = = 1.06 x 106 is correct. I was thinking does the shuttle really have a flight path of 8000km as the question says? The distance from atmosphere to Earths surface is much less isn't it ?? Had a quick look on internet and looks like 400 km
Yes, but does the shuttle come to a complete stop in outer space and then fall straight to the ground? That's the only way the distance on re-entry becomes 400 km.
 
  • #5
SteamKing said:
Yes, but does the shuttle come to a complete stop in outer space and then fall straight to the ground? That's the only way the distance on re-entry becomes 400 km.

Oh I see ... the shuttle does not just drop onto Earth perpendicular to a point on the surface. It flies in an orbit around the Earth so the path is 8000 km
 
  • #6
Barclay said:
Oh I see ... the shuttle does not just drop onto Earth perpendicular to a point on the surface. It flies in an orbit around the Earth so the path is 8000 km
You got it, except the Shuttle is technically no longer in orbit.

The great length of this path is designed so that the Shuttle bleeds off the kinetic energy from orbiting the Earth and slows down to a manageable landing speed by the time it reaches its landing field. The Shuttle is not powered after re-entry to the atmosphere and glides to its final destination.
 

1. Why is the book answer for the work = Fd question incorrect?

The book answer for the work = Fd question may be incorrect because it is based on theoretical calculations and assumptions. In reality, there are many factors that can affect the amount of work done, such as friction, air resistance, and other external forces. Additionally, the formula may not account for the complexities of the situation, such as the changing velocity and direction of the object.

2. How does the space shuttle entry affect the calculation of work = Fd?

The entry of the space shuttle into the Earth's atmosphere introduces many variables that can affect the calculation of work = Fd. These include the changing velocity and direction of the shuttle, the resistance of the atmosphere, and the effects of air friction. These variables make it difficult to accurately calculate the work done by the shuttle during entry.

3. What are some alternative methods for calculating the work done during the space shuttle entry?

One alternative method for calculating the work done during the space shuttle entry is to use real-time data and measurements from the shuttle itself. This would provide a more accurate representation of the work done since it takes into account the actual conditions and variables present during the entry. Another method is to use computer simulations and models to calculate the work done based on the known physical properties of the shuttle and its surroundings.

4. How does the concept of work = Fd apply to the space shuttle entry?

The concept of work = Fd still applies to the space shuttle entry, as it is a fundamental principle of physics. However, due to the complexities and changing conditions of the entry, it may not be as straightforward to calculate as in simpler scenarios. The formula may need to be modified or alternative methods may need to be used in order to accurately calculate the work done.

5. Can the work done during the space shuttle entry be accurately calculated?

It is difficult to accurately calculate the work done during the space shuttle entry due to the many variables and complexities involved. However, with advancements in technology and more precise measurements, it may be possible to get closer to an accurate calculation. It is important to remember that the concept of work = Fd is still applicable, but may not always produce an accurate result in real-world situations.

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