Question

The position coordinate of a moving particle is given by x=6+18t + 9t²(Where x is in meters and t is in seconds) what is the velocity at t=2 second?

The displacement (in metre) of a particle moving along x-axis is given by x=18t+5t². Calculate (i) the instantaneous velocity t=2s (ii) average velocity between t=2s to t=3s (iii) instantaneous acceleration.