Topic 3.4: Materials

Question 1

what is meant by extension and compression of a string ?

Answer 1

tensile forces act away from the centre of the spring in both directions and will stretch it out causing the spring to extend

forces acting towards the centre of the spring in both directions is called compression

Question 2

what happens to the spring when tensile/compressive forces are exerted

Answer 2

the spring undergoes tensile deformation (for tensile forces) or compressive deformation (for compressive forces)

Question 3

what is Hooke’s Law ?

Answer 3

force applied is directly proportional to the extension in length , up to the limit of proportionality

Question 4

what is meant my tensile stress ?

Answer 4

the force per unit area

Question 5

what is tensile strain ?

Answer 5

a measure of how the material stretches: the extension divided by the original length

Question 6

elastic deformation

Answer 6

when the force is removed the object will its original shape

Question 7

plastic deformation

Answer 7

after the force is removed , the object will not return to its original shape