solids and fluids

Question 1

define elasticity

Answer 1

when an object has equal and opposite forces, changes size, shape.
e.g. balloon stretches

Question 2

what is the equation for stress

Answer 2

Stress= F/A

Question 3

equation for tensile strain

Answer 3

delta L/ L(original)

Question 4

if L>Lo what is the tensile strain direction

Answer 4

positive

Question 5

for compressive strain and L<Lo what is the direction

Answer 5

negative

Question 6

what is compressive strain due to

Answer 6

pushing stress

Question 7

stress is _____ to strain

Answer 7

proportioanl

Question 8

what is the equation for young’s module

Answer 8

compressive stress/ compressive strain

Question 9

what is the units for young’s modulus

Answer 9

Nm^-2

Question 10

what are the four things that define young’s module for material

Answer 10

1. when stress is proportional to strain
2. does not depend on shape, size or volume of the object
3. does depend on the material of the object
4. is a measure of the stretchiness of material

Question 11

what is inelastic behaviour

Answer 11

when material is stretched or compressed but doesn’t return to normal state - remains deformed

Question 12

what is elastic limit

Answer 12

stress beyond permeant deformation