Question

can you check this for me?


The volume of a cone is three hundred cubic kilometers. If the radius of the base is 5 kilometers, what is the height of the cone? Use three point one four for pi. Show your work and round to the nearest tenth.

Answer 1

Radius, r = 9 km.
Volume, V = 300 cu. km.
Height = h

V = 1/3 π r² h
h = V / (1/3 π r²)

Subbing known values,

h = 300 / [1/3 π (9)²]
h = 300 / [1/3 π (81)
h = 300 / 84.823
h = 3.53

Answer 2

is this correct?

Answer 3

i dont understand how in the ...... heck did the radius suddenly turn into 9km from 5km

Answer 4

\[\large V = \frac13 \pi r^2 h\]\[\large \frac{3V}{\pi r^2}=h\]

Answer 5

Use that formula for h...

Answer 6

\[\large V = 300 \ km^3\]\[\large r=5 \ km\]\[\large \frac{3(300)}{\pi (5)^2}=h\]

Answer 7

\[\large h = \frac{900}{25\pi}\] Now solve.

Answer 8

What do you get?..