Determine the tension in the coupling

  • Thread starter Thread starter navjot
  • Start date Start date
  • Tags Tags
    Coupling Tension
AI Thread Summary
To determine the tension in the coupling of a train with 50 cars, each weighing 6.6e3 kg and accelerating at 1.5e-1 m/s², the formula F=ma is applied. For the tension between the 30th and 31st cars, the calculation involves using (51-n) where n represents the car number, leading to a total force of 19800 N. There is confusion regarding the correct application of the formula for the tension between the 49th and 50th cars, with some suggesting that n should equal 2. Clarification indicates that the correct approach is to use 50-n instead of 51-n for the last car. The discussion emphasizes the importance of correctly identifying the car numbers in the calculations.
navjot
Messages
2
Reaction score
0
A train consists of 50 cars, each of which has a mass of 6.6 e3 kg. The train has an acceleration of 1.5 e-1 m/s2. Ignore friction and determine the tension in the coupling at the following places. (a) between the 30th and 31st cars

(b) between the 49th and 50th cars



F=ma



I got the first part by using the equation: (51-n)*ma = 20*6.6e3*1.5e-1 = 19800. But I can't seem to get part (b). Wouldn't n be 2?
 
Physics news on Phys.org


Why 2 ?
The train is 50 cars, the 50th is the last one.
It's really obvious.

Also this is not correct, why 51-n ? 50-n.
(51-n)*ma
 


Quinzio said:
Why 2 ?
The train is 50 cars, the 50th is the last one.
It's really obvious.

Also this is not correct, why 51-n ? 50-n.
(51-n)*ma

so when I had to find the acceleration of the 31st car, I did 51-31= 20, and 20*ma was correct. So if I need the acceleration of the 50th car, would I do 51-50?
 
Last edited:

Thread 'Errors and significant figures'

I multiplied the values first without the error limit. Got 19.38. rounded it off to 2 significant figures since the given data has 2 significant figures. So = 19. For error I used the above formula. It comes out about 1.48. Now my question is. Should I write the answer as 19±1.5 (rounding 1.48 to 2 significant figures) OR should I write it as 19±1. So in short, should the error have same number of significant figures as the mean value or should it have the same number of decimal places as...
View full post »
Thread 'A cylinder connected to a hanging mass'

Thread 'A cylinder connected to a hanging mass'

Let's declare that for the cylinder, mass = M = 10 kg Radius = R = 4 m For the wall and the floor, Friction coeff = ##\mu## = 0.5 For the hanging mass, mass = m = 11 kg First, we divide the force according to their respective plane (x and y thing, correct me if I'm wrong) and according to which, cylinder or the hanging mass, they're working on. Force on the hanging mass $$mg - T = ma$$ Force(Cylinder) on y $$N_f + f_w - Mg = 0$$ Force(Cylinder) on x $$T + f_f - N_w = Ma$$ There's also...
View full post »

Similar threads

How Is Tension Calculated Between Train Cars During Acceleration?
Replies
1
Views
3K
Forces and Newton's Laws of a train
Replies
10
Views
6K
Finding friction and tension for a train
Replies
1
Views
2K
Tension on a Massive Rope: How to Calculate Tension at Different Points
Replies
11
Views
3K
What is the tension in the lift cable and in the string?
Replies
19
Views
3K
Newton's law problem: Pushing 2 stacked blocks on a horizontal table
Replies
13
Views
3K
Tension force and acceleration Problem
Replies
1
Views
2K
What is the relationship between tension and mass in a system with friction?
Replies
6
Views
2K
Tension force of block and rope
Replies
25
Views
5K
Why Does Tension Vary Along the Rope in a Hanging Superhero Scenario?
Replies
5
Views
7K

Hot Threads

Recent Insights

Back
Top