80 railway wagons all of same mass 5*103 are pulled by a force 4*105 N . the tension in coupling between the 30 and the 31 wagon from the engine is
( ans= 25*104 N)
From Newton's second law,
F=ma
or 4x105 =80 x 5000 x a
a=1 m/s2
Tension developed in the coupling between 30th and 31st wagon will be due to the mass of remaining 50 wagons.
Now mass of the remaining 50 wagons=50 x 5000=250000 kg
Hence required tension=250000 x 1=250000 N=25 x 104 N