elasticity

Question 1

what is shear stress

Answer 1

• shear stress makes layers of fluid slide over each other
• a shear stress force is parallel to an area

Question 2

unit for viscocity

Answer 2

pascal seconds

Question 3

what is hooke’s law

Answer 3

for a material within its elastic limit, the force applied is directly proportional to the extension of the material

Question 4

equation for extension using force

Answer 4

Extension = Force/stiffness

Question 5

what happens to the force of the string as the stiffness increases

Answer 5

• as the stiffness on a spring increases, more newtons of force an are required to stretch the spring
• a stiffer spring has a steeper gradient

Question 6

elastic definition

Answer 6

the object can return to its original shape after being stretched

Question 7

what is the yeild point

Answer 7

the point where the material begins to experience permanent deformation

Question 8

equations for youngs modulus

Answer 8

youngs modulus = stress / strain
ym = FL / Ax
F = force, L = length, A = area, x = extension

Question 9

why is a longer wire required for the youngs modulus experiment

Answer 9

• it allows a greater extension with the same force for safety and cost
• this gives larger measurements relative to the resolution which decreases the percentage uncertainty

Question 10

equation for stress

Answer 10

stress = force / cross sectional area

Question 11

equation for strain

Answer 11

strain = extension / original length