Final answer:
The optimal target face velocity for a standard laboratory hood is 100 fpm, which allows for safe and effective removal of hazardous fumes without disrupting sensitive experiments.
Step-by-step explanation:
The target face velocity for a standard laboratory hood is typically around 100 feet per minute (fpm). This rate is considered optimal for maintaining safety in laboratory environments, as it assists in the removal of hazardous fumes while not being so fast as to disturb delicate experiments or processes. In the context of airflow, laminar flow which is characterized by smooth, parallel layers of flow is defined by a Reynolds number less than 2000. In some given examples, such as a nozzle with 1.27×105, and a hose with 3.51×104, the flow is not laminar as indicated by their Reynolds numbers being above this threshold. However, when the Reynolds number, like 2.54, is significantly less than 2000, the flow is considered laminar.