Answer:
0.45 m/s in the negative x-direction
Explanation:
From the law of conservation of momentum, the sum of initial momentum equals the sum of final momentum
Momentum, p=mv where m is the mass and v is the velocity
where is the common velocity, and are velocities of magnet moving in positive x-direction and magnet moving in negative x-direction respectively, and are masses of magnet moving in positive x-direction and magnet moving in negative x-direction respectively.
Substituting 125 g for and 85 g for , 7.33 m/s , -11.9 m/s for then
Therefore, the velocity of single unit is 0.45 m/s in the negative x-direction