A ball of mass 0.40 kg rolls towards a wall with a velocity of +2.0 m/s, hits the wall, and bounces back at the same speed. What is the change in momentum of the ball? 1.6 kg m/s

-1.6 kg m/s

-3.2 kg m/s

0 kg m/s

Which of the following is an example of units for speed

One object has a mass of 1 kg and another object has a mass of 3 kg. if the speeds are the same, which of the following is true about their kinetic energy?

Two forces produce equal torques on a door about the door hinge. the first force is applied at the midpoint of the door; the second force is applied at the doorknob. both forces are applied perpendicular to the door. which force has a greater magnitude?