Barron's 2nd Edition DT Q38

Barron's Book

38) This question requires us to use the conservation of momentum to solve for the resulting speed after the following collision. We can start with our conservation of momentum equation.

Where p is momentum, m is mass, and v is velocity

Additionally, since the carts travel together after the collision, we can rewrite the equation to include this.

Where m is mass, and v is velocity

Finally, we can plug in the given values to solve for the final speed.

Where v is velocity

Answer: B