Aglob of sticky putty is thrown against a slightly open door so that it sticks on impact and gives the door a momentum of 1.4 kg m/s. a rubber ball with exactly the same mass and velocity as the sticky putty strikes the door and bounces back at its initial speed in the opposite direction. what impulse does it impart to the door?

2.8 kgm/s

1.4 kgm/s

0.70 kgm/s

0 kgm/s

Complete these sentences. if a roller coaster train has a potential energy of 1,500 j and a kinetic energy of 500 j as it starts to travel downhill, its total energy isj. once the roller coaster train gets closer to the bottom of the hill, its kinetic energy increases to 1,100 j, and its potential energy decreases to j. when the train reaches the bottom of the track and is traveling along the ground, its kinetic energy isj.