Answer:

Explanation:
The formula for the surface of the circle is:

The rate of change of the spill area is obtained by deriving the previous formula in terms of time:

Finally, variables are replaced by known data:


Explanation:
It is given that,
Mas of the object, m = 6 kg
It is lifted through a distance, h = 5.25 m
Tension in the string, T = 80 N
(a) By considering the free body diagram of the object, the forces can be equated as :




Work done by tension, 


(b) Work done by gravity, 


(c) Let v is the final speed of the object and u = 0


v = 5.91 m/s
Hence, this is the required solution.
Answer:
ummm I didn't understand the question