Which of the following examples describes an increase in potential energy?

a. a bicycle going down a hill

b. a basketball falling through a net

c. a rollercoaster moving down the track

d. a paint can being carried up a ladder

A6.0-kilogram cart initially traveling at 4.0 meters per second east accelerates uniformly at 0.50 meter per second squared east for 3.0 seconds. what is the speed of the cart at the end of this 3.0 second interval? (1) 1.5 m/s (3) 3.0 m/s (2) 5.5 m/s (4) 7.0 m/s