If the maximum stress in the elastic limit for a piece of plastic is 350 MPa (mega-Pascals), what will happen to the plastic after it is subjected to a 355 MPa stress? A. It will permanently deform.
B. It will return to its original shape.
C. It will fracture.
D. It depends on the strain.

correct it is c.) b b

when two balls of the different masses are dropped from equal height, they reach the ground at the same time .this is because they experience the same acceleration.

the acceleration is independent of mass.

thus when they are dropped they will always maintain the same velocity and travel the same distance (neglect air resistance of course) at the same time.

conservation of mass

mass before something happens = mass afterwards