A tank, shaped like a cone has height 11 meter and base radius 4 meter. It is placed so that the circular part is upward. It is full of water, and we have to pump it all out by a pipe that is always leveled at the surface of the water. Assume that a cubic meter of water weighs 10 000 N

The tank is a cone, so the radius of the cross section increases linearly with h

At y=0, r=4 and at y=11, r=0

So

r(y)=4/11 (11−y)

A(y)=π[4(11−y)11]^2

Integral will be:

11∫0 (1000)(9.8)(4πy^2)(25)(11−y)dy

Step-by-step explanation:

not only in mathematics, scientific proof also are required in the other field of science. also maths proofs are of particular structure, containing steps and logics. so proving is like doing science, it is science. that's why it is important to prove. 

an inaccurate proof leads to errors, or stating results that are not accurate.  which wil mess the probelm up you dont want this