Explanation:

Velocity-time graph:
A velocity-time graph is a graph that represents the relationship between velocity and time. The velocity is plotted on the y-axis, and time is plotted on the x-axis. The graph shows how the velocity of an object changes over time.

Area under the graph:
The area under a velocity-time graph represents the displacement or the distance traveled by an object. The displacement is the change in position of an object, which can be positive or negative depending on the direction of motion.

Unit of area:
The unit of area under a velocity-time graph can be determined by looking at the units on the axes. In this case, the velocity is measured in meters per second (m/s) and time is measured in seconds (s).

To calculate the area under the graph, we multiply the velocity (m/s) by time (s). The product of these two units is meters (m), which represents the distance traveled by the object.

Example:
Let's consider an example to understand this concept. Suppose we have a velocity-time graph where the velocity is constant at 10 m/s for a duration of 5 seconds.

The area under the graph can be calculated as follows:
Area = Velocity x Time
Area = 10 m/s x 5 s
Area = 50 m

The area under the graph represents the distance traveled by the object, which in this case is 50 meters.

Conclusion:
Therefore, the area under a velocity-time graph is represented by the unit of meters (m). This unit represents the distance traveled by an object over a given period of time.