Answer
See the detailed answer below.
Work Step by Step
a) The given formula appears as a conservation of momentum of two objects that are stuck together after they hit each other.
- Two clay balls are moving in the same direction one of them has a mass of 400 g and is moving to the right at a speed of 3 m/s, and the other one has a mass of 200 g and is moving at a speed of $v_{ix,2}$. Find $v_{ix,2}$ if you know that the two balls will stick together after the collision and will move as one unit at a speed of 4 m/s toward the east.
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b) See the pictorial representation below.
$$v_{ix,2}=\dfrac{(600\times 4)-(400\times 3)}{200}=\color{red}{\bf 6}\;\rm m/s$$
And it is also toward the east since it is positive.
