Question

Problem 11b

Answer 1

Given information

Take the difference between area of the silo’s base and the area of the pile’s base.

find area of the pile then find the required rate.

Height of silo is h=100 ft

radius r=200 ft

radius of ore 1.5 h

Step-by-step explanation

Step 1.

When the pile is 60 feet high,the radius at its base is 90 feet.

floor area left

 

Let the pile’s area be represented as  A

 

Now, the area of the pile’s base is circular

 

 

............(1)

dA(h)dt=dA/dh.dh/dt      ..............(2)

from (1)