Question 143823
The distance traveled by a ball rolling down a ramp is given by s(t)=3.5t^2, where t is the time in seconds after the ball is released, and s(t) is measured in feet. 
Find the distance the ball has rolled in 1 second.
s(1) = 5 ft.
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Find the distance the ball has rolled in 1.5 seconds. 
s(1.5) = 5*1.5^2 = 11.25 ft.
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Find the average velocity of the ball in the interval from 1 second to 1.5 seconds
Average = (11.25 - 5)/(1.5-1) = 6.5/0.5 = 13 ft per second
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Cheers,
Stan H.