A velocity-time (v-t) graph is a type of graph that compares how velocity changes over a period of time. The vertical axis of the graph represents the velocity of the object, while the horizontal axis represents time. The specific features of the motion of objects are demonstrated by the shape and the slope of the lines on a v-t graph. Here are some key points to keep in mind when interpreting v-t graphs:

• A horizontal (flat) line indicates that the object is traveling at a constant speed.
• A straight diagonal line indicates that the objects velocity is changing.
• The slope of the line on a v-t graph is equal to the acceleration of the object.
• When the slope is steep, the object will be changing velocity rapidly. When the slope is shallow, the object will not be changing its velocity as rapidly.
• If the slope is negative, the acceleration will be negative, and if the slope is positive, the acceleration will be positive.

The shape of the v-t graph can reveal important information about the motion of an object. For example, a motion described as a constant, positive velocity results in a line of zero slope (a horizontal line has zero slope) when plotted as a v-t graph. Furthermore, only positive velocity values are plotted, corresponding to a motion with positive velocity.