How can you calculate average speed from a distance time graph
The Correct Answer and Explanation is :
To calculate the average speed from a distance-time graph, you use the formula:
[
\text{Average Speed} = \frac{\text{Total Distance}}{\text{Total Time}}
]
In a distance-time graph, the distance is plotted on the y-axis, and the time is plotted on the x-axis. Here’s the step-by-step process to find the average speed:
- Identify the total distance: Look at the graph and note the final distance value. This is typically where the line stops along the y-axis.
- Identify the total time: Check the x-axis for the time it took to cover the distance. This corresponds to the final point on the graph’s line horizontally.
- Divide distance by time: Use the total distance and total time values in the formula.
Example:
If a person travels 60 kilometers over 3 hours, you can calculate their average speed as:
[
\text{Average Speed} = \frac{60 \text{ km}}{3 \text{ hours}} = 20 \text{ km/h}
]
Explanation:
A distance-time graph shows how far an object has traveled over a period. The slope (or gradient) of the graph at any point indicates the speed at that moment. If the graph is a straight line, the object is moving at a constant speed, and the slope is the same throughout. The steeper the line, the faster the object is moving. If the graph is curved, the speed is changing, and you’d have to calculate average speed over a given interval.
Key Concept:
- Average speed does not account for changes in speed along the way. It simply gives you the overall rate of movement over the entire journey.
- If the motion is uniform, the average speed will be the same as the speed at any given point. In non-uniform motion, the object may move faster or slower at different points, but the average speed still provides an overall picture of the movement.
Thus, from a distance-time graph, simply find the total distance traveled and divide it by the total time to compute the average speed.