Cube Volume Rate 32A74C
1. **State the problem:**
We are given a cube whose side length is increasing at a rate of 12 m/s. We need to find the rate at which the volume of the cube is increasing when the side length is 4 cm.
2. **Identify variables and given data:**
Let $s$ be the side length of the cube (in meters), and $V$ be the volume of the cube (in cubic meters).
Given:
- Rate of change of side length: $\frac{ds}{dt} = 12$ m/s
- Side length at the instant: $s = 4$ cm = 0.04 m (converted to meters)
3. **Formula for volume of a cube:**
$$V = s^3$$
4. **Differentiate volume with respect to time $t$ to find rate of change of volume:**
$$\frac{dV}{dt} = 3s^2 \frac{ds}{dt}$$
5. **Substitute known values:**
$$\frac{dV}{dt} = 3 \times (0.04)^2 \times 12$$
6. **Calculate:**
$$\frac{dV}{dt} = 3 \times 0.0016 \times 12 = 0.0576$$
7. **Interpretation:**
The volume of the cube is increasing at a rate of $0.0576$ cubic meters per second when the side length is 4 cm.
**Final answer:**
$$\boxed{\frac{dV}{dt} = 0.0576 \text{ m}^3/\text{s}}$$