Grain is pouring out of a silo at a constant rate of 4 m^3/min. As it falls, the grain forms a conical pile that has a radius twice its height. How fast is the radius increasing when the radius is 7 m?I am not getting the answer at the back of the book: the answer is 8/49pi m/min. Thanks
haha, you're lucky I was on this for another questions, so u get a quick reply. ok, so the radius is 7, so the height is 3.5. Calculate the volume of the cone. pi*r^2 *height. 49*pi*3.5. You get 171.5 pi is the volume. Divide 171.5 by 7 (the radius) and you get how many minutes it takes for the radius to grow one meter. (6.125 minutes). But you want how fast the radius is growing. So simple 1/6.125= 8/49m/min. I'll leave the transfering of the unit pi to you. Goodluck!
