differential equations – Why does mathematica not display the graph?

I want to substitute the solution of a differential equation into a function, and plot the function.
My code is as attached:

teta=NDSolveValue({(Theta)''(t) == (m l (g -i ((Theta)'(t))^2 Cos((Theta)(t))) (Sin((Theta)(t)) - (Mu)k Cos((Theta)(t))))/(i +m l^2 Sin((Theta)(t))(Sin((Theta)(t)) - (Mu)k Cos((Theta)(t))))
, (Theta)(0) == (Pi)/2, (Theta)'(0) == 0} /. {m -> 0.03517,l -> 0.0279,g -> 9.81,i -> 10.^-3 ,(Mu)k -> 0.1827}, (Theta) , {t, 0, 5})

F(t) =={ m l ((Theta)''(t) Cos((Theta)(t)) - (Theta)(t)'^2 Sin((Theta)(t)))} /. (Theta)(t) -> teta//Simplify

 

The code works until here. When I try to plot F(t), mathematica only displays the axes but not the graph itself. Please send help. Thank you.