In a distance vs. time graph, the speed is represented by the slope of the graph (speed = change in distance / change in time). - Part A (O-A): The graph is a straight line with a positive slope, indicating constant positive speed. The slope is relatively steep. - Part B (A-B): The graph is a horizontal line, meaning the distance is not changing over time. The slope is zero, indicating the car is stopped (vb = 0). - Part C (B-C): The graph is a straight line with a positive slope, indicating constant positive speed. The slope is less steep than in Part A. Comparing the slopes: Slope of A > Slope of C > Slope of B (which is 0). Therefore, va > vc > vb. Looking at the options, D) va > vb; va > vc is the only option that correctly reflects the relationship va > vc and va > vb (since vb = 0).
Consider a journey by a car represented by the graph given below in three parts A, B and C. The speed of the car in these parts is va, vb and vc, respectively : [Image shows a Distance vs Time graph with segments O-A, A-B, B-C representing the journey parts] Which one of the following is correct in this case ?
Asked in UPSC CDS 2 2023 · Topic: Mechanics (Newton's Laws of Motion and their applications)
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