question_answer

From the graph given below find the average velocity between 10s and 30s.

Answer:

Average velocity between 10s and 30s \[=\frac{dis\tan ce\,\,travelled}{Time\,\,taken}\] Distance travelled in 10s to 30s = area of trapezium AFEB + Area of trapezium CDEB \[=\frac{1}{2}(AF+BE)\times FE+\frac{1}{2}(CD+BE)\times DE\] \[=\frac{1}{2}(21+12)cm{{s}^{-1}}\times 5s+\frac{1}{2}(21+12)cm{{s}^{-1}}\times 15s=\frac{1}{2}\times 33\times 5cm+\frac{1}{2}\times 33\times 15cm\] \[=(82.5+247.5)cm=330cm\] Total time taken = 20 seconds. \[\therefore \] Average velocity \[=\frac{330cm}{20s}=16.5cm/s\]