The instantaneous angular position of a point on a rotating wheel is given by the equation ` theta (t) = 2t^3 - 6t^2 . ` The torque on the wheel becomes zero at : .......... .

Options

A. `t = 1s`
B. `t = 0.5 s`
C. `t = 0.25 s `
D. `t = 2s`

Answer

A

Explanation

According to equation , torque ` tau = 0` it means that ` prop = (d^2)/( dt^2)`
here , ` theta = 2t^3 - 6t^2`
` alpha = (d^2)/(dt^2) (2t^3 - 6t^2) = 12t = 12`
` [ prop = (d^2 t)/(dt^2) = 0 ] = 12t - 12 = 0`
` therefore t = 1s `