Plz help me with this problem

Hi, thank you for your question.

Here is how I would respond to this question.

As you were able to successfully get the first part of the question, I assume that you are able to use related rates of change to solve the question. I think you may have used the value of d(theta)/d(t) in degrees when solving for part (b), which would be incorrect and consistently give you wrong values. If that is the case, you would get an answer around 26199 ft/s. If this is the answer you were repeatedly getting, remember, when doing derivatives, use radians.

Does this answer your question?