Answer:
h = 5 cm
Step-by-step explanation:
Given that,
The volume of ice-cream in the cone is half the volume of the cone.
Volume of cone is given by :
![V_c=\dfrac{1}{3}\pi r^2h](https://tex.z-dn.net/?f=V_c%3D%5Cdfrac%7B1%7D%7B3%7D%5Cpi%20r%5E2h)
r is radius of cone, r = 3 cm
h is height of cone, h = 6 cm
So,
![V_c=\dfrac{1}{3}\pi (3)^2\times 6\\\\V_c=18\pi\ cm^3](https://tex.z-dn.net/?f=V_c%3D%5Cdfrac%7B1%7D%7B3%7D%5Cpi%20%283%29%5E2%5Ctimes%206%5C%5C%5C%5CV_c%3D18%5Cpi%5C%20cm%5E3)
Let
is the volume of icecream in the cone. So,
![V_i=\dfrac{18\pi}{2}=9\pi\ cm^3](https://tex.z-dn.net/?f=V_i%3D%5Cdfrac%7B18%5Cpi%7D%7B2%7D%3D9%5Cpi%5C%20cm%5E3)
Let H be the depth of the icecream.
Two triangles formed by the cone and the icecream will be similiar. SO,
![\dfrac{H}{6}=\dfrac{r}{3}\\\\r=\dfrac{H}{2}](https://tex.z-dn.net/?f=%5Cdfrac%7BH%7D%7B6%7D%3D%5Cdfrac%7Br%7D%7B3%7D%5C%5C%5C%5Cr%3D%5Cdfrac%7BH%7D%7B2%7D)
So, volume of icecream in the cone is :
![V_c=\dfrac{1}{3}\pi (\dfrac{h}{2})^2(\dfrac{h}{3})\\\\9\pi=\dfrac{h^3}{12}\pi\\\\h^3=108\\\\h=4.76\ cm](https://tex.z-dn.net/?f=V_c%3D%5Cdfrac%7B1%7D%7B3%7D%5Cpi%20%28%5Cdfrac%7Bh%7D%7B2%7D%29%5E2%28%5Cdfrac%7Bh%7D%7B3%7D%29%5C%5C%5C%5C9%5Cpi%3D%5Cdfrac%7Bh%5E3%7D%7B12%7D%5Cpi%5C%5C%5C%5Ch%5E3%3D108%5C%5C%5C%5Ch%3D4.76%5C%20cm)
or
h = 5 cm
So, the depth of the ice-cream is 5 cm.