Forced landing of a plane - Find the minimum length of the barage

Click For Summary

Homework Help Overview

The problem involves a 1000 kg plane attempting a forced landing on a 2000 kg barge at rest on a calm sea. The scenario includes a constant frictional force between the plane's wheels and the deck, which is one-quarter of the plane's weight. The objective is to determine the minimum length of the barge required for the plane to stop safely after touching down at a speed of 50 m/s.

Discussion Character

  • Exploratory, Assumption checking, Problem interpretation

Approaches and Questions Raised

  • Participants discuss the implications of the barge's movement upon touchdown and whether it can be assumed to move without friction through the water. There are attempts to apply conservation of momentum and energy principles to analyze the situation, with some participants expressing uncertainty about their approaches.

Discussion Status

The discussion is ongoing, with various interpretations being explored regarding the movement of the barge and the calculations needed to determine the stopping distance. Some participants have provided calculations, while others seek clarification on the assumptions and methods being used.

Contextual Notes

There is a lack of consensus on whether the barge's movement affects the calculations and how to account for the frictional forces involved. Participants are also navigating the constraints of the problem setup and the information provided.

Aqua Marine
Messages
8
Reaction score
0

Homework Statement


A 1000 kg plane is trying to make a forced landing on the deck of a 2000kg barage at rest on the surface of a calm sea. The only frictional force to consider is between the plane's wheels and the deck, and this braking force is constant and equal to one-quater of the plane's weight. What must the minimum length of the barage be, in order that the plane can stop safetly on the deck, if the plane touches down just at the rear end of the deck with a velocity of 50m/s towards the front of the barage?

Homework Equations





The Attempt at a Solution

 
Physics news on Phys.org
You need to show some work before we can help. How about trying to fill in numbers 2 and 3 of the above template?
 
If the barge is allowed to move when the plane touches down - are we to assume it moves without 'friction' through the water ?
 
i have no clue abt what i have to do :(
 
i did tried solving the questions and I did it the following way:

Pi=Pf
(Mc x Vc)+(Mc x Vc)= (Mc x Vl) x Vcl
30 000kgm/s /2000 kg = Vcl

15m/s = Vcl


Ei = Ef
kinetic enerygy = mgh
0.5(2000)(15 x 15) = ( 2000 x 9.8 m/s) h
(225000 kgm/s2) / (19600 kgm/s2)
= 11.5 kgm/s2
 
please let me no if its right or wrong...thank you
 
To calculate the stopping distance you can use energy conservation.
The stopping is done by friction, and the work done by friction is force*distance.

This work is equivalent to the kinetic energy of the plane when it touches down. Equate the work and energy and you can compute the distance. You can also find the time it takes to stop.

I'm ignoring any movement of the barge. If the barge moves ( and I think it will) then the distance above can be reduced by the amount the barge moves from the touchdown to the plane stopping. This distance is given by 1/2at^2 where a = f/M,
f = mu.m.g and M and m are the masses of the barge and plane and t is the time to stop.
 
Last edited:

Similar threads

  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 8 ·
Replies
8
Views
2K
  • · Replies 8 ·
Replies
8
Views
2K
  • · Replies 7 ·
Replies
7
Views
4K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 1 ·
Replies
1
Views
4K
Replies
7
Views
4K
  • · Replies 5 ·
Replies
5
Views
2K
Replies
5
Views
2K