1. Acceleration measures how fast velocity changes
Section 1.3 Outline
Acceleration measures how fast velocity changes

2. I. Speed and direction can change with time
acceleration: the rate at which velocity changes with time
if velocity does NOT change, there is NO acceleration
direction of acceleration determines how an object’s motion changes

3. 3) direction of acceleration determines how an object’s motion changes
acceleration in same direction as motion = increase in speed
acceleration in opposite direction of motion = decrease in speed
acceleration at a right angle to motion = change in direction AND no change in speed

4. II. Acceleration can be calculated from velocity and time
to measure acceleration you need to know how velocity changes with time
change in velocity found by subtracting the final and initial velocities
time interval can be measured as the velocity changes
acceleration measures the change in velocity, not velocity itself

5. A. Calculating Acceleration
Acceleration = final velocity – initial velocity
time
A = VFinal- VInitial T
Velocity is expressed in units of meters per second (m/s)
Acceleration is expressed in units of meters per second per second (m/s2)
A negative sign indicates a negative acceleration meaning a decrease in velocity

6. C. Velocity – Time Graphs
Rising line indicates positive acceleration or an increase in velocity
Flat line indicates no acceleration or constant velocity
Falling line indicates negative acceleration or a decrease in velocity