Final answer:
The height of the sand cone is increasing at a rate of 192 cm³/sec when the height is 4 cm.
Step-by-step explanation:
Let's denote the height of the sand cone as h and the radius of the base as r.
Given that the height of the cone is always 16th of the radius of the base, we can write the equation h = (16/1) * r = 16r.
To find how fast the height of the sand cone is increasing, we need to differentiate the equation h = 16r with respect to time t.
Using the chain rule, we get dh/dt = 16(dr/dt).
Hence, the rate at which the height is increasing is 16 times the rate at which the radius is increasing.
We are given that dr/dt = 12 cm³/sec, so substituting this value into the equation, we get
dh/dt = 16 * 12
= 192 cm³/sec.
Therefore, the height of the sand cone is increasing at a rate of 192 cm³/sec when the height is 4 cm.