The $4-$inch by $6-$inch timber has a unit weight of $38\frac{H}{f}{t}^3$ and is held in a horizontal position by the concrete anchor. The length, $L$ is $42$ feet. Calculate the minimum weight that the concrete anchor must be in order to hold the timber in the horizontal position under water as shown in the figure below. Assume that concrete $y=150\frac{\text{\#}}{f}{t}^3.$

$84$ pounds

$110$ pounds

$146$ pounds

$279$ pounds

Problem cannot be solved, not enough information is given