I'm not sure about the first word as 'contribute' seems strange but maybe it makes sense in context. I think it's Hindi or something in the middle. ... contribute is the y-component of the velocity, so the normal component is just the y-component, OK? So Q ... [I don't think this is English] ... now the one leading at different shapes between these two points, between B and C, ...

Velocity is an example of what is known as a "vector". It is what you use to describe the speed and direction of a moving object. You can think of it like an arrow. It points in the direction in which the object is moving, and its length (always nonnegative) is the speed of the object. When you analyze the motion of an object in two dimensions, a velocity vector is represented by two numbers, such as (3,4) which would mean that the direction is 3 in the x-direction (the x-component) and 4 in the y-direction (the y-component). Using the Pythagorian Theorem, the length of the vector would be 5 because 5^2 = 3^2 + 4^2. Thus its speed would be 5.