"Sample code 1: Generate the list of the coordinates of a 2D projectile and ListPlot the list "
theta=45.0Degree;v0=5.0;x0=0.0;y0=0.0;g=-9.81;
T=-2(y0+v0*Sin[theta])/g;
Deltat=0.05T;
x[t_,theta_]:=x0+v0*Cos[theta]*t;
y[t_,theta_]:=y0+v0*Sin[theta]*t+0.5*g*t^2;
list=Table[{x[t,theta],y[t,theta]},{t,0,T,Deltat}];
ListPlot[list]

list
list[[12]]
list[[12,2]]
list[[12,1]]

"Sample code 2: Displying the trajactory of a 2D projectile using Manipulate "
theta=45.0Degree;v0=5.0;x0=0.0;y0=0.0;g=-9.81;
T=-2(y0+v0*Sin[theta])/g;
Deltat=0.01T;
x[t_,theta_]:=x0+v0*Cos[theta]*t;
y[t_,theta_]:=y0+v0*Sin[theta]*t+0.5*g*t^2;
list=Table[{x[t,theta],y[t,theta]},{t,0,T,Deltat}];
lpp[t_]:=ListPlot[{{x[t,theta],y[t,theta]}},PlotStyle->Red,PlotMarkers->{"×",Large},PlotRange->{{0,x0+v0*T*Cos[theta]},{0,y[T/2,theta]}}];

ListPlot[list]

Manipulate[
Show[{lpp[t]}],{t,0,T,Deltat}]

Manipulate[
Show[{lpp[t],ListPlot[list]}],{t,0,T,Deltat}]

"Sample code 3: Extract information of the elements in the list"
Length[list]
list[[2]]
list[[2,1]]
list[[2,2]]
list[[-1]]

"We can form the list of y using Table and defining elemy[i_]:=list[[i,2]]:"
elemy[i_]:=list[[i,2]];
tabley=Table[elemy[i],{i,1,Length[list]}]

"What is the largest value in y? We can find the maximum of y, ymax using Max[tabley]: "
ymax=Max[tabley]

"Another way to find ymax: Using sort:"
"tabley=" 
tabley
"Sort[tabley]="
Sort[tabley]
"The last emement in the output of Sort[tabley] is the largest value of y in tabley"

"Sort[tabley][[-1]]="
Sort[tabley][[-1]]

"Where in tabley is ymax sitting? That is, what is the the index such that tabley[[index]]=ymax?"
"This can be obtained using Ordering[]. It gives the positions in list at which each successive element of Sort[list] appear"

tabley
Sort[tabley]
"Ordering[tabley]="
Ordering[tabley]

lot=Ordering[tabley][[-1]]

"It says the last element in Sort[list] is sitting in position 51 in list. We can check that indeed this is the case by printint out tabley[[lot]], where"
" lot=Ordering[tabley][[-1]] = "
lot=Ordering[tabley][[-1]]
"tabley[[lot]]="
tabley[[lot]]
"This shows that indeed tabley[[lot]] is ymax"

"So, now, can you figure out what is the corresponding value of x at which y=ymax in the list?"

list[[lot]]

xmax=list[[lot,1]]