final speed of the 3.0 kg cart is 2.67 m/s .
<u>Step-by-step explanation:</u>
Here we have , A 2.0 kg cart moving right at 5.0 on a friction less track collides with a 3.0 kg cart initially at rest. The 2.0 kg cart has a final speed of 1.0 to the left. We will use law of conservation of momentum: For a collision occurring between object 1 and object 2 in an isolated system, the total momentum of the two objects before the collision is equal to the total momentum of the two objects after the collision.
⇒
⇒
⇒
⇒
⇒
⇒
Therefore, final speed of the 3.0 kg cart is 2.67 m/s .