Chapter 8 - Deforming solids

Question 1

what is a compressive force

Answer 1

spring is being squashed

Question 2

what is a tensile force

Answer 2

stretching of a spring

Question 3

how can a material obey hookes law

Answer 3

material obeys hookes law if the extension of the material is directly proportional to the force applied until the elastic limit is reached

Question 4

what is the force constant of a spring

Answer 4

gradient of force against extension graph

Question 5

how can you work out the force constant of the spring

Answer 5

force constant = force/extension

Question 6

what is the equation for strain

Answer 6

strain = extension/original length

Question 7

what is the equation for stress

Answer 7

stress = force/cross sectional area

Question 8

what is young modulas

Answer 8

this is a measure of stiffness of the material, constant for a material no matter size

Question 9

what is equation for young’s modulas

Answer 9

stress/strain

Question 10

what is elastic behavior

Answer 10

will stretch and return to original lenght

Question 11

what is plastic deformation

Answer 11

when it stretched but will not return to its original length

Question 12

what are ductile materials

Answer 12

when stretched will become permanently deformed

Question 13

what are brittle materials

Answer 13

they break at the elastic limit

Question 14

what is plastic behaior

Answer 14

will stretch

Question 15

what does the strength of a material show us

Answer 15

what stress will be required to break the material

Question 16

what is elastic potential energy

Answer 16

when object stretched it gains energy, will transfer energy when released

Question 17

how can you work out work done from force against extension graph

Answer 17

area under the graph

Question 18

what is the ultimate tensile strength

Answer 18

the maximum stress that an object can withstand