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Question
A particle moves along a straight line in such a way that after t seconds its distance from the origin is s = 2t2 + 3t metres. Find the average velocity between t = 3 and t = 6 seconds
Solution
s = 2t2 + 3t
Average velocity between t = 3 and t = 6 seconds
Now s(t) = 2t² + 3t
Average velocity = `("s"(6) - "s"(3))/(6 - 3)`
= `([2(6^2) + 3(6)] - [2(3^2) + 3(3)])/3`
= `((72 + 18) - (18 + 9))/3`
= `(90 - 27)/3`
= `63/3`
= 21 m/s
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