Question 1103942
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S = 0 every time when {{{(pi*t)/2}}} = {{{pi/2}}}, {{{3pi/2}}}, {{{5pi/2}}}, {{{7pi/2}}},  which corresponds to values of t = 1, 3, 5, 7 seconds.


<U>Answer</U>.  S = 0  at  t = 1 second,  3 seconds,  5 seconds  and  7 seconds in the interval from 0 to 8 seconds.
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