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 'Voltmeter readings for this circuit with switches'
TL;DR Summary: I would like to know the voltmeter readings on the two resistors separately in the picture in the following cases , When one of the keys is closed When both of them are opened (Knowing that the battery has negligible internal resistance) My thoughts for the first case , one of them must be 12 volt while the other is 0 The second case we'll I think both voltmeter readings should be 12 volt since they are both parallel to the battery and they involve the key within what the...
Thread 'Correct statement about a reservoir with an outlet pipe'
The answer to this question is statements (ii) and (iv) are correct. (i) This is FALSE because the speed of water in the tap is greater than speed at the water surface (ii) I don't even understand this statement. What does the "seal" part have to do with water flowing out? Won't the water still flow out through the tap until the tank is empty whether the reservoir is sealed or not? (iii) In my opinion, this statement would be correct. Increasing the gravitational potential energy of the...
Back
Top