Question

last questio

Answer 1

So similar to the last question, we need to first find the radius

and THEN we need to find the diameter

volume = 1/3 * pi * h * r^2

volume is 20 * pi
height is 10

so

20 * pi = 1/3 * pi * 10 * r^2

can you first solve for r

Answer 2

for a first step, you can divide pi on both sides of the equal sign

Answer 3

can you walk me through it?

Answer 4

did you understand how I plugged in the numbers to get

20 * pi = 1/3 * pi * 10 * r^2

Answer 5

yeah

Answer 6

volume = 1/3 * \(\pi\) * h * r^2

volume is 20\(\pi\)
height is 10

20\(\pi\) = 1/3 * \(\pi\) * 10 * r^2

so what happens if you divide \(\pi\) on both sides?

it should cancel out!

so what are you left with?

Answer 7

2.4?

Answer 8

no uh idk if you're saying that's the final answer because I haven't yet gotten there but

\( 20\times \cancel{\pi} = \dfrac{1}{3} \times \cancel{\pi} \times 10 \times r^2\)

do you see how they cancel out since we have a pi on both sides?

so we're left with

\( 20 = \dfrac{1}{3} \times 10 \times r^2\)


does that make sense?

Answer 9

yeah

Answer 10

so we want to get r^2 all by itself

so what do you get if multiply 3 on both sides



do you see how the 1/3 gets cancelled out when we multiply by 3 on both sides?

so we're left with 20 * 3

which is what?

Answer 11

60

Answer 12

good

now we have

60 = 10 * r^2

now divide 10 on both sides

what is 60/10 = ?

Answer 13

6

Answer 14

so we now have

6 = r^2

and to solve for r, we have to take the square root on both sides

so r = ??

what is sqrt(6) = ?

Answer 15

2.4

Answer 16

you should always always keep extra digits

UNTIL you get to the last and final step

that's when you round to one digit or how many ever digits they want you to have

Answer 17

mk

Answer 18

because that's the radius

and they want us to find the diameter

and the diameter is 2 times the radius

Answer 19

if we just go by 2.4

then you would get 4.8 as your final answer

however the radius is actually 2.4495

so what is 2 times that?

Answer 20

so 4.9

Answer 21

exactly!!

so if you had kept it as 2.4 then you would end up with 4.8 which is close to the correct answer but just not quite it

so good job, 4.9 is your final answer :)

Answer 22

thanks

Answer 23

you're most welcome!

Answer 24

:)

Answer 25

gn