sentences:  Thus Knowing quantitatively the burning rate of a propellant, and how it changes under various conditions, is of fundamental importance in the successful design of a solid rocket motor.The concept of Burning rate is also relevant in case of liquid propellants.One device for measuring burning rate is a V shaped metal channel about 1–2 feet long wherein a sample is placed, with a cross-sectional dimension of approximately 6 mm or 1/4".