Final answer:
Airflow in the boundary layer is affected by friction, surface shape, and air velocity.
Step-by-step explanation:
Airflow in the boundary layer is affected by several factors. One of the main factors is the friction between the air and the surface over which it is flowing. This friction creates a slow-moving layer of air called the boundary layer. The thickness of this boundary layer affects the airflow and can impact the performance of objects like wings or sails. Additionally, the shape of the surface and the velocity of the air also play a role in determining the airflow in the boundary layer.