Which of the following is an external effect of a force? 0 A rubber ball became distorted after it was kicked. 0 An elastic string is pulled at both ends causing the string to elongate. O NONE OF THE CHOICES O A man pushes an unlocked door causing the door to open. 0 A chain composed of several links is pulled at both ends. As a consequence of which each linked exerted a force on the links connected to it. A quantity which represents a measure of the elongation or contraction of an arbitrary line segment in a body under deformation. O normal strain O Poisson's Ratio O Shear Strain O Proportional Limit O Elastic Modulus O none of the choices