In this lecture internal forced convection is addresses. Lecture 2 of 6. It concentrates on entrance effects of laminar flow and the influence of the Prandtl number. This lecture is Lecture 10 (2016) of six lectures on heat transfer that was based on the textbook of Cengel and Ghajar (5th edition) and was presented as part of a heat transfer class to the fourth year students of the Department of Mechanical and Aeronautical Engineering by Prof Josua Meyer, Head of the Department of Mechanical and Aeronautical Engineering of the University of Pretoria, South Africa. Lecture was presented on 5 April 2016.