Final answer:
When the conservation of momentum is applied to the collision of two masses with equal mass, it can be determined that mass B will come to rest (0 m/s) after the collision.
Step-by-step explanation:
The question pertains to conservation of momentum during a collision. According to the law of conservation of momentum, in the absence of external forces, the total momentum of a system remains constant. In the given scenario, mass A and mass B have equal masses but different velocities before the collision. After the collision, mass A is moving with a speed of 4 m/s in the -x-direction.
To find the final velocity of mass B after the collision, we can set up the conservation of momentum equation:
mA * uA + mB * uB = mA * vA + mB * vB
Given that mass A and mass B have equal masses and the velocities are provided, we can substitute the values:
(mA)(2 m/s) + (mA)(-6 m/s) = (mA)(-4 m/s) + (mA)(vB)
Since the masses are equal and non-zero, we can cancel them out:
2 m/s - 6 m/s = -4 m/s + vB
-4 m/s = -4 m/s + vB
Therefore, vB = 0 m/s. Mass B comes to rest after the collision.