1. **Problem Statement:** The speed of a nerve impulse in the human body is about 100 m/s. Estimate the time it takes the nerve impulse to travel to your brain if you stub your toe. 2. **Formula Used:** Time is calculated by the formula $$t = \frac{d}{v}$$ where $t$ is time, $d$ is distance, and $v$ is velocity. 3. **Assumptions:** The average distance from the toe to the brain is approximately 1 meter (this is an estimate for calculation). 4. **Calculation:** Using the formula, $$t = \frac{1 \text{ m}}{100 \text{ m/s}} = 0.01 \text{ s}$$ 5. **Explanation:** This means the nerve impulse takes about 0.01 seconds (10 milliseconds) to travel from the toe to the brain, which is very fast and explains why you feel pain almost immediately after stubbing your toe. **Final Answer:** The nerve impulse takes approximately $0.01$ seconds to travel to the brain.