Note the Physics

• If the acceleration is constant, the velocity vs. time "curve" is straight since its slope must be constant.
• Regions of the velocity graph that have upward slope correspond to positive acceleration and vice versa. Downward sloping regions of the velocity graph correspond to negative acceleration.
• Positive acceleration does not necessarily mean that the object speeds up. (What does positive or negative acceleration mean?)
• The value of the acceleration depends on the slope of the velocity, but not the initial value of the velocity.