Freya has a mass of 14kg she is running at 1.1m/s to the left when she runs into Eric, who is standing still. Eric has a mass of 18kg. After the collision, they continue moving together. What is their velocity after the collision.

A. 0.48 m/s to the left

B. 2.5 m/s to the left

C. 0.86 m/s to the left

D. 1.4 m/s to the left

Their final velocity is 0.48 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, assuming right side velocity as positive, and left side velocity as negative.

14 * (-1.1) + 18 * (0) = (14+18) v

v=-0.48 m/s

Here, negative sign indicates that they both will move in left direction.