Question

32.
The trains travelling on the same track are approaching each other with equal speeds of 40m/s. The
drives of the trains begin to decelerate simultaneously when they are just 2.0 km apart. Assuming the
decelerations to be uniform and equal, the value of the deceleration to barely avoid collision should be -
(A)
11.8 m/s
(B)
11.0 m/s
(C)
2.1 m/s2
(D)
0.8 m/s​

Answer 1

Answer:

0.8 m/s this is your answer

Answer 2

In such qstions of relative velocity always bring to rest one object.Suppose u bring the car coming frm rite to rest by applying 40m/s in the opposite direction.To balance this imaginery velocity to rite car u have to add the same velocity to the other car in the same direction so the other car will now have speed 80m/s.So nw one car is at rest nd the other car is moving wid 80m/s nd u need to avoid collision n they are 2000m apart.So applying,

v2=u2+2as

0=(80)^2 + 2*a*2000

-6400=4000a

a=1.6m/s2