Thank you so much for your reply. the code successfully plotted for angle'[t] and speed'[t] but the x[t], and y[t] are not displayed.
There are four dependent variables angle[t], speed[t], x[t], and y[t] but only two equations. You need to specify equations for angle'[t] and speed'[t]. There is a Wolfram Demonstrations Project on the Flight of a Glider that might help.
angle[t]
speed[t]
x[t]
y[t]
angle'[t]
speed'[t]
