Ignoring air resistance, the bullet's horizontal velocity is constant:
[tex]v_x=v_{0x}=100\,\dfrac{\mathrm m}{\mathrm s}[/tex]
In 1.3 seconds, we can expect it to travel
[tex]v_xt=\left(100\,\dfrac{\mathrm m}{\mathrm s}\right)(1.3\,\mathrm s)=130\,\mathrm m[/tex]
