Question 784441
A rollercoaster car decelerates uniformly from a velocity of 20 m/s to come to rest while covering a displacement of 40 m.  What was the acceleration of the car?
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v = at --> t = v/a
s = at^2/2
Sub for t
s = a*(v/a)^2/2
s = v^2/2a
a = v^2/2s = 400/(2*40)
a = 5 m/sec/sec