Question

A body of mass 1 kg moving with a velocity of 10 m/s towards right makes a head on collision with another body of mass 3 kg and velocity 2m/s coming from the opposite direction. Calculate the velocity of each after impact and also the loss in kinetic energy for each cases i) they stick together ii) the collision is perfectly elastic​

Answer 1

Answer:

option A

Explanation:

Given :            m  

1

​  

=2kg         m  

2

​  

=1kg           u  

1

​  

=3  m/s        u  

2

​  

=4   m/s

Let the common velocity of the combined body be V

Mass of combined body      M=2+1=3kg

Applying conservation of momentum :          

2×3−1×4=3×V              ⟹V=  

3

2

​  

   m/s

Momentum of the system     P=2×3−1×4=2 kg m/s

Loss in kinetic energy of the system due to collision         ΔK.E=K.E  

i

​  

−K.E  

f

​  

 

 ΔK.E=  

2

1

​  

(2)×3  

2

+  

2

1

​  

(1)×4  

2

−  

2

1

​  

(3)×(  

3

2

​  

)  

2

 

⟹ΔK.E=  

3

49

​  

  J