Question

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

Answer 1

Answer:

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    

$V = -\dfrac{v}{3}$      

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

hence, the correct answer is option B.