MCQ
Among the four graphs Fig. there is only one graph for which average velocity over the time intervel $(0, T )$ can vanish for a suitably chosen $T.$ Which one is it?
- A
- ✓
- C
- D
✓
Answer
Correct option: B.
We need to identify the graph in which there is one displacement for different timings. it means that these displacements would be in opposite directions and when we add these opposite displacements, net displacement would be zero or average velocity would be zero. This thing is only possible in the graph $(b).$
If we draw a line parallel to time axis from the point $(A)$ on the graph at $t = 0$ sec. This line can intersect graph again at $B.$ At this point, the change in displacement $(O - T)$ time is zero i.e., displacement at $A$ and $B$ are equal so as the change in displacement is zero so the average velocity of body vanishes to zero.
If we draw a line parallel to time axis from the point $(A)$ on the graph at $t = 0$ sec. This line can intersect graph again at $B.$ At this point, the change in displacement $(O - T)$ time is zero i.e., displacement at $A$ and $B$ are equal so as the change in displacement is zero so the average velocity of body vanishes to zero.
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