A) \[\text{8}\,\text{m/min}\]
B) \[6\,\text{m/min}\]
C) \[\frac{8}{3}\,\text{m/min}\]
D) \[\text{2}\,\text{m/min}\]
Correct Answer: D
Solution :
Key Idea: The average velocity is defined as total displacement of the body in a particular time interval divided by the time interval. Displacement from 0 to \[5\text{ }s=40\text{ }m\] Displacement from 5 to \[10\text{ }s=40\text{ }m\] Displacement from 0 to \[15\text{ }s=-\text{ }20\text{ }m\] and displacement from 15 to\[~20\text{ }s=0\,m\] \[\therefore \] Net displacement \[=40+40-20+0=60\,m\] Total time taken \[=5+5+15+5=30\text{ min}\] Hence, average velocity \[=\frac{\text{displacement(m)}}{\text{time(min)}}\] \[=\frac{60}{30}=2m/\min \]You need to login to perform this action.
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