1. Draw a sketch.

2. According to my sketch the point P has the coordinates P(x, 10+y).

3. Since the argument of the sine function is an angle measured against(?) the horizontal axis the argument here must be when you calculate the x-coordinate.

4. According to the text of the question a blade of the mill makes a full turn in 24 s. If T is measured in seconds the angle is calculated by:

5. Since the argument of the cosine function is an angle measured against(?) the horizontal axis the argument here must be when you calculate the y-coordinate.

6. Therefore you have:

7. Since you are only interested in the height above ground you'll get: