This table shows us that we can reach the target which is out at 3,000 ft. Our maximum landing point is around 3030 ft when k is somewhere between 700 and 900. So we can surely hit our target at 3,000 ft out, but exactly what value of k should we use? We now focus our table on the interval 400 to 500.

Input := 


TableForm[Table[{k, x[t,k]/.Solve[ y[t,k]==0,t] [[2]]//N},

	 	{k,400,500,10}] ,

	TableHeadings->{None,{"x-coord","landing pt"}}]

Output =


   x-coord   landing pt

   400       2987.69


   410       2989.94


   420       2992.12


   430       2994.23


   440       2996.26


   450       2998.23


   460       3000.12


   470       3001.94


   480       3003.7


   490       3005.39


   500       3007.02