Posted by James on .
if a particle moves along a line so that at time t where t [0,pi] its position is given by s(t)=4costt^2/2+10 what is the velocity of the particle when its acceleration is zero?
so i found
v(t) = 4sintt
a(t)=4cost1 = 0 solved for t plugged it into v(t) and i got the wrong answer i got 3.2 something but the choices are
5.19
.74
1.32
2.55
8.13
please help thank you

calckinematics 
Reiny,
Did you have your calculator set to radians ?
I get
t = arcsin(1/4)
= 1.318116
then
v(1.318116) = 4sin(1.318116)  1.318116
= 2.55486
close to one of the choices,
(they should have rounded to 2.56)