  Over a field of characteristic p>2, firstly, the structure of Kac modules of
Lie superalgebra $\tilde{P}(2)$ and the weight space decompositions are given.
Secondly, the weight-derivations of $\tilde{P}(2)$ to its Kac modules are
computed. Finally, the first cohomology of $\tilde{P}(2)$ with coefficients in
Kac modules is determined.
