Given that the position function of a particle in motion is s(t)=cost-16t^2 where t is measured in seconds and s(t) is measured in feet find the particle's initial acceleration

Question

How is it -33 ft/s

Answer 1

s(t)=cost-16t^2
v(t) = s'(t) = -sint-32t
a(t) = v'(t) = -cost-32
now plug in t=0