3. What does Newton's first law explain? a. Why roller coaster start with a big hill.
b. Why roller coasters an cause damage to the human body.
c. Why roller coasters need constant pulling to stay moving.
d. Why roller coasters are fun.

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.

technology is the application of the knowledge gained by science.