What does the term “agony of defeat” mean to you?

The noun agony means acute pain — either mental or physical, but people often use the word hyperbolically: "This paper cut is agony." The noun agony is also used in the common phrase "the thrill of victory and the agony of defeat," which has been the tag-line of ABC's Wide World of Sports for decades.

Explanation:

it is called kinetic energy

the chart show the masses and velocities of two colliding objects that stick together after a collision.

according to the law of conservation of momentum, the momentum of the object after the collision is  

answer

1,500

kg • m/s.