Sorry but i myself dont know the answer.

Well the experts will give the answer thats for sure.

 

but i do it in the following way ( plz see where am i getting the question wrong)

 

Suppose the horizontal distance is k

then when the string is paid out, it forms a rt triangle and

we get

=30 (sin 30=60/120)

also,

tan  =60/k

or =tan^ -1(60/k)

now

d/dt=d/dk * dk/dt

=d(tan^ -1 (60/k))/dk * dk/dt

using calculator( i dont know how to get derivative of tan inverse)

i get,

answer= 1.19 degrees/sec

so where am i getting the answer wrong (i am not sure of my method, it looks a bit wrong. i dont know where but it looks so)