Question

Question was provided via image upload.

Explanation:

1. For the first blank: In an isolated system (net external force = 0) during a collision, momentum is conserved. This is the law of conservation of momentum. So the word is "momentum".
2. For the second blank: When two objects collide and stick together (like the fullback and linebacker here), they travel "together" after the collision.
3. For the third blank: By the law of conservation of momentum, the total momentum after the collision is equal to the total momentum before the collision. The total momentum before is 20 kg m/s left, so after it is also "20" kg m/s left.
4. For the fourth blank: The fullback's momentum before collision is 100 kg m/s right, and the linebacker's is 120 kg m/s left. The linebacker's momentum (120) is more than the fullback's (100) before the collision. So the answer is "more".
5. For the fifth blank: Since the total momentum is 20 kg m/s left (because linebacker's momentum was more in the left direction), the players move in the direction the "linebacker" was moving (left direction).

Answer:

1. momentum
2. together
3. 20
4. more
5. linebacker