_9. An example of a system having both kinetic and potential energy would be: a a book resting on a table S an object in free fall b. a projectile at its highest point d. a stretched rubber band _10. On building, as the elevator decelerates downward its a kinetic energy increases and work increases b. kinetic energy decrease and work decreases S. kinetic energy increases and potential energy decreases d. kinetic energy decreases and potential energy decreases

_9. An example of a system having both kinetic and potential energy would be: a a book resting on a table S an object in free fall b. a projectile at its highest point d. a stretched rubber band _10. On building, as the elevator decelerates downward its a kinetic energy increases and work increases b. kinetic energy decrease and work decreases S. kinetic energy increases and potential energy decreases d. kinetic energy decreases and potential energy decreases