Question

2.two equal masses 2 kg each moving with a speed of 10 metre per second and 5 metre per second in opposite direction collide elastically.find the velocity after collision...

please answer this guys... this is my 6th posting of this question.. all are giving irrelevant answers.... ​

Answer 1

Answer:

7.5 m/s

Explanation:

Mass of object 1st = 2kg

Mass of object 2nd = 2kg

Velocity of 1st object before collision = 10 m/s

Velocity of 2nd object before collision = 5 m/s

So, Total momentum before collision

= mass of object 1st * velocity of object 1st + mass of object 2nd * velocity of object 2nd

= 2kg * 10 m/s + 2kg * 5m/s

= 20 kg.m/s + 10 kg. m/s

= 30 kg. m/s

Let the velocity after collision be 'x'

So, total momentum after collision

= 2 kg * x + 2 kg *x

= x( 2 kg + 2 kg)

= 4x

So, by law of conservation of momentum

Total momentum before collision = Total momentum after collision

therefore,

30 = 4x

So, x = 7.5

Hence, Velocity of both object after collision is 7.5 m/s