Acceleration is the rate of change in an object's velocity, either in speed or direction. It is measured in meters per second squared and can be positive if an object speeds up with acceleration and velocity in the same direction, or negative if an object slows down with acceleration and velocity in opposite directions. A wood roller coaster has a lower velocity than a steel roller coaster, sways more, and lacks loops or steep hills, while a steel roller coaster has a higher velocity, is more rigid, and includes inversion loops and steeper hills.

1. Acceleration Physical Science Section 2.2

2. Acceleration Acceleration- change in velocity Change in speed or direction or both Positive and negative acceleration Positive- speeding up- velocity and acceleration occur in the same direction Negative- slowing down Velocity and acceleration occur in opposite directions

3. Acceleration Acceleration- has direction, just like velocity Acceleration – rate of change in velocity Acceleration= change in velocity/time a = (v f – v i ) / t Units of a: m/s 2 Units of v: m/s Units of t: s

4. Acceleration Graphs: constant speed: zero acceleration, positive acceleration, negative acceleration

5. Acceleration Wood Roller Coaster- Lower velocity Sways more No loops or steep hills Steel Roller Coaster- Higher velocity More rigid Inversion loops and steep hills