A roller coaster is moving at 25 m/s at the bottom of a hill. Three seconds later it reaches the top of the hill moving at 10 m/s. What was the acceleration of the coaster?

What is this question asking us to find?

A roller coaster is moving at 25 m/s at the bottom of a hill. Three seconds later it reaches the top of the hill moving at 10 m/s. What was the acceleration of the coaster?

How would you find the change in velocity?

A train moves from rest to a speed of 25 m/s in 30.0 seconds. What is its acceleration?

In this problem, the object was_____ so the acceleration should be ______