Find the work done by nonconservative forces in stopping the plane.


by stuckne1
Tags: distance, force, joules, work
stuckne1
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#1
Sep27-10, 08:08 PM
P: 3
1. The problem statement, all variables and given/known data
Find the work done by nonconservative forces in stopping the plane.

A 18000 {\rm kg} airplane lands with a speed of 92 {\rm m/s} on a stationary aircraft carrier deck that is 115 {\rm m} long.


2. Relevant equations
W = FD


3. The attempt at a solution

18000 * 92 * 115 = 190440000 J

Unless it's wanting 1.9 * 10^8 = 190000000 J (which seems wrong since detail is lost)

(I don't think that's 2 significant digits.)
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berkeman
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#2
Sep27-10, 08:24 PM
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Quote Quote by stuckne1 View Post
1. The problem statement, all variables and given/known data
Find the work done by nonconservative forces in stopping the plane.

A 18000 {\rm kg} airplane lands with a speed of 92 {\rm m/s} on a stationary aircraft carrier deck that is 115 {\rm m} long.


2. Relevant equations
W = FD


3. The attempt at a solution

18000 * 92 * 115 = 190440000 J

Unless it's wanting 1.9 * 10^8 = 190000000 J (which seems wrong since detail is lost)

(I don't think that's 2 significant digits.)
The best way to solve this type of problem is with energy considerations. What was the KE of the plane just before it traps on the carrier deck? What is the KE right after it is stopped by the wire? Wher did that energy go?
stuckne1
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#3
Sep27-10, 09:04 PM
P: 3
it was 1/2(m)(v)^2 or something.

The answer was -7.6 x 10 ^7

Thanks!

berkeman
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#4
Sep27-10, 09:07 PM
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Find the work done by nonconservative forces in stopping the plane.


Quote Quote by stuckne1 View Post
it was 1/2(m)(v)^2 or something.

The answer was -7.6 x 10 ^7

Thanks!
Does that mean that you calculated the correct answer? What are the units of the answer?
stuckne1
stuckne1 is offline
#5
Sep28-10, 07:02 AM
P: 3
Yes, the units of the correct answer was in joules.


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