My name is Gul and i am a student in grade 9(secondary).I have some math problems. here are the question i am have problem with !!

  1. Sand for use on icy roads is stored in a conical pile 14.2 m high and with a base diameter of 34.4 m
    • calculate the volume of the pile

    • if one sander can take 6.9 m of sand, how many sanders can be filled from the pile?

thanks alot,
Gul

Hi Gul,

The volume of a cylinder (tin can) is the area of the base times the height. Since the base is a circular disk this gives the area of a cylinder as

This seems quite natural to me, a cylinder is a "stack of disks" so its volume is the area of the disk times the height.

The volume of a cone is

where r is the radius of the base and h is the height. Notice that the volume of the is one-third the volume of the cylinder.

Since your cone has height 14.2 m and the radius of the base is 34.4/2 m, the volume is

In your second problem I think that the sanders can each take 6.9 cubic meters of sand.

Cheers,
Penny
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