Chapter 5

Question 1

forces acting on solids

Answer 1

when the force is applied to materials, the size and shape of the material can change(deformation) eg: stretch, squash, bend, twist and shear
Tension = a pulling or stretching action
Compression =a pushing or crushing action
Bending =folding which results from an applied force
Torsion = a twisting action
Shear =tearing or sliding from opposing forces

Question 2

stretching springs

Answer 2

• at first the springs deforms eleastically. it will return to its original length when the load is removed
• but when the load is increased too far, the spring becomes permanently stretched and will not return to original shape (ineleastically deformed)
• this is the Limit Of Proportionality

Question 3

Hookes law

Answer 3

the extension of a spring is proportional to the applied force (force = spring constant x extension of spring or F = k x X)
-many materials obey hookes law like metal wires
hookes law is associated with the initial linear part of force-extension graph

• objects that obey hookes law will return to original length after being stretched
• if an object continues to be stretched it an be taing past the limit of proportionality/elastic limit. at this point it will not obey hookes law as it will not return to original length