two blocks A and B of masses 2kg and 10 kg moving in opposite direction colloid held on - the velocity of A and B just after collision is 10 metre per second and 2 metre per second respectively .
what is the final velocity if the two blocks stick after collision.
Answers
Solution is in the pic....
Answer: 0 m/s
Concept: conservation of momentum
Given:
Mass of block A: 2Kg
Mass of block B: 10Kg
Velocity of block A before collision: 10 m/s
Velocity of block B before collision: 2m/s
To find: final velocity after collision , Vf
Explanation:
let,
MA is the mass of block A: 2 Kg
MB is the mass of block B: 10 Kg
VA is the velocity of block A before collision: 10m/s
VB is the velocity of block B before collision: -2 m/s
(The -ve sign is due to the block B moves in the opposite direction w.r.t A )
Acc. to law of conservation of linear momentum
pf = pi
pi = MA*VA + MB*VB
pf = (MA + MB)*Vf
(MA + MB)*Vf = MA*VA + MB*VB ........(1)
put the above values in equation (1)
2*10 + 10*(-2) = (2=10)*Vf
20 - 20 = 12Vf
0 = 12Vf
0/12 = =Vf
=> Vf = 0 m/s
Hence, the final velocity, Vf is 0 m/s.
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