@?materials

Recall Questions Define Hooke’s law?? The extension of a spring is directly proportional to the force applied, provided the elastic limit of the spring is not exceeded. Define extension?? The difference between the final and initial length of an object. Define elastic deformation?? The material returns to its original shape and size after any applied forces are removed. Define plastic deformation?? The material will not return to its original shape and size after any applied forces are removed.

Flashcards What is a loading and unloading curve?? A graph that shows how extension varies with force as a material is being stretched and released. Why is there a difference between the loading and unloading curves for an elastic band?? More work is done stretching (loading) the elastic band than releasing (unloading) it. What is the loop formed between the unloading and loading curves called?? A hysteresis loop. What is tensile stress?? The force applied per unit cross-sectional area of a material.

What types of forces alter an object?? A pair of equal and opposite forces. Why do you need to equal and opposite forces to alter an object?? Because otherwise you’d just move the object. When you’re sitting on a chair, you’re compressing it. What are the two forces in action?? Your weight The normal reaction from the ground What are forces that produce extension called?? Tensile forces. What are forces that shorten or compress an object called?