# Thread: volume cone hw ?

1. ## volume cone hw ?

A construction company wants to know how much sand is in a pile. The company measures that the distance from the edge of the pile at ground level to the very top of the pile is 55 ft. The company also measures that the distance around the pile at ground level is 220 ft.

a.) How much sand is in the pile?

b.) The construction company has trucks that carry 10 cubic yards in each load. How many loads will it take to move the pile of sand? Explain

for a i came up with 54454.2 cubic feet and then for b i got 202 truck loads. I am not sure if they are right, but can someone please try this and give me some feedback??? Is one cubic yard equal to 27 cubic feet?

2. Originally Posted by igottaquestion
A construction company wants to know how much sand is in a pile. The company measures that the distance from the edge of the pile at ground level to the very top of the pile is 55 ft. The company also measures that the distance around the pile at ground level is 220 ft.

a.) How much sand is in the pile?

b.) The construction company has trucks that carry 10 cubic yards in each load. How many loads will it take to move the pile of sand? Explain

for a i came up with 54454.2 cubic feet and then for b i got 202 truck loads. I am not sure if they are right, but can someone please try this and give me some feedback??? Is one cubic yard equal to 27 cubic feet?

Recall: $\displaystyle C=2\pi{r}$

You were given $\displaystyle C=220ft$, so find $\displaystyle r$.

Also note that $\displaystyle r$ and $\displaystyle 55ft$ respectively form the leg and the hypotenuse of a right triangle so that the hieght $\displaystyle h$ of the pile can be found by

$\displaystyle (55)^2-r^2=h^2$.

The Volume of the pile: $\displaystyle V=\frac{1}{3}\pi{r}^3$

3. i got r=110/pie

i thought the volume of a cone is 1/3 pie r squared h???
is this not right?

what did you get for the volume of the pile...i got 54454.2 cubic feet

4. Originally Posted by igottaquestion

i thought the volume of a cone is 1/3 pie r squared h???
is this not right?
All I can say to that is......oops. You are correct. $\displaystyle V=\frac{1}{3}\pi{r^2h}$. Sorry about that.

5. have you looked at part b?

6. Originally Posted by igottaquestion
have you looked at part b?
You mean $\displaystyle V/10$? I gave it a thought. Oh, but dont forget to convert.