During a collision, a bus runs into a skateboarder inelastically. If the mass of the skateboarders is 70 kg and is moving at 12 m/s to the right, what is the final velocity of the skateboarder if the 2000 kg bus is traveling at 25 m/s to the left before the collision?

The final velocity of the skateboarder is 23.75 m/s.

We can use conservation of momentum to calculate the magnitude of the final velocity.

Momentum before collision is equal to the momentum after collision

m1v1+m2v2 = (m1+m2) v

here, v is final velocity of the skateboarder, assuming right side velocity as positive, and left side velocity as negative.

70*12+2000 * (-25) = (70+2000) v

v=-23.75 m/s

Here, negative sign indicates that both skyboarder and bus will move in left direction.