Bijay Shrestha

If 4.t is the correct answer then here is my soln.(Someone said 4.5 is wrong but i think its correct) velocity of bird neglecting fish vertical rise =6m/s mu= A/r(in this case since bird in in rarer medium) 4/3=a/r (4/3)dr/dt=da/dt dr/dt=6*3/4 4.5