Question

You pour a quantity of flour of volume 72 onto a board where it forms a conical pile the coefficient of static friction is pi find the maximum height

Answer 1

The volume of a conical pile is changing as wheat is being pored from the chute so you are probably going to need an expression for the volume of a cone. The volume of a cone is given by V = 1/3 π r2 h where r is the radius of the base and h is the height.

In your situation you know that the radius is half the height so the volume expression can be changed to

V = 2/3 π r3

You are asked how fast the circumference is changing so you are going to need an expression for the circumference of a circle. The circumference of a circle is given by

C = 2 π r

These are not static equations, they are dynamic. As you pour wheat onto the pile V changes so r changes which forces C to change. In other words V, r and C are all functions of time t.

Answer 2

u can find height by Pyth. Thoeram or by C=2πr