<p>hey, i have a question. a particle is moving s(t)= -2sin(-t^2/4) + 10. What is the velocity when acceleration is zero? much help is appreciated.</p>
<p>v(t) = s'(t). Use the chain rule:
s = -2sin(u) / u = (-t^2)/4
s' = -2cos(u) / u' = -t/2
s'(t) = s'.u' = tcos(-t^2/4)
a(t) = v'(t). Use the product rule and the chain rule.
a(t) = 0. Find the value(s) of t and substitute it/them in v(t).</p>
<p>i tried setting a(t) equal to zero but i don't know how to solve for t. cuz i get t^2cos(-t^2/4) + sin(-t^2/4).</p>
<p>Could it be... infinity? I don't think that particle has a terminal velocity (as visible from the graph of v(t)).</p>
<p>oh i forgot, t is from -pi/2 to pi/2. sorry bout that</p>