The Laplace transform of $f(t)= 2\sqrt{t/\pi}$ is $s^{-3/2}$. The Laplace transform of $g(t)=\sqrt{1/\pi t}$ is.
1. $3s^{-5/2} /2$
2. $s^{-1/2}$
3. $s^{1/2}$
4. $s^{3/2}$