The position equation for the movement of a particle is give by s=(t^2)^3 when s is measured in feet and t is?

Question

measured in seconds. Find the acceleration at two seconds.
please explain steps. thank you.
A. 342
B. 18
C. 288
D. 90

Answer 1

d^2s/dt^2=30t^4=30*16=480'/secY2

Answer 2

s=(t^2)^3
s=t^6
v = ds/dt = 6*t^5
a = dv/dt = 30*t^4
for t = 2, a = 480

Are you sure the formula is s = (t^2)^3?