Question

A line rotates in a horizontal plane according to the equation theta=2t^3 -6t,where theta is the angular position of the rotating line, in radians ,and t is the time,in seconds. Determine the angular acceleration when t=2sec.

A.) 6 radians per sec^2
B.) 12 radians per sec^2
C.) 18 radians per sec^2
D.) 24 radians per sec^2 << my choice.

Answer 1

θ=2t^3-6t

θ'=dθ/dt=6t²-6

θ"=d²θ/dt²
=12t

θ(2)=12*2=24 radians-sec^-2