TDE11 Find the expression for the instantaneous velocity for the distance-time function x = kt³ − lt² + mt and evaluate the velocity at t = 1 s. Take k = 2 m/s³, l = 4 m/s² and m = 5 m/s.

The general expression for the velocity is the time derivative of the x = f(t), or

and the velocity evaluated at t = 1 s is