The two blocks of masses m and 2m shown above initially travel at the same speed v but in opposite directions. they collide and stick together. what is the final velocity of the mass m after the collision? a. -1/6v. b. -1/3v. c. 1/6v. d. 1/3v. figure: two box are colliding

option B.

Explanation:

given,

Mass of the blocks 1 = M

Mass of the blocks 1 = 2 M.

initial speed of the block 1= v

initial speed of the block 2 = - v

where V is the final speed of the blocks after collision

using conservation of momentum

M v + 2 M (-v) =  (M + 2 M) V

3 M V = - M v    

velocity of the blocks after collision is equal to -v/3 m/s

hence, the correct answer is option B.

an obstruction