Amaterial is said to be ductile if it

A material is said to be ductile if it can be stretched thin when tensile stress is administered. Such a material can be stretched into a wire.

 This is different from malleability which describes a material that can bend or alter shape using compressive force e.g. hammering , rather than tensile stress.

Tensile stress is a type of force or stress that alters the length of a material in the same direction as the force being applied. 

The opposite of ductile is brittle. Brittle materials can break when subjected too much tensile stress.

the bal will not change its velocity.