Rectilinear Motion In Exercises $81-84,$ consider a particle moving along the $x$ -axis where $x(t)$ is the position of the particle at time $t, x^{\prime}(t)$ is its velocity, and $x^{\prime \prime}(t)$ is its acceleration.
A particle moves along the $x$ -axis at a velocity of $v(t)=1 / \sqrt{t}$ , $t>0$ . At time $t=1,$ its position is $x=4 .$ Find the acceleration and position functions for the particle.