ch6 materials

Question 1

what are tensile forces

Answer 1

forces that produce extension

Question 2

what are comprehensive forces

Answer 2

forces that shorten an object

Question 3

tensile deformation

Answer 3

when tensile forces are exerted

Question 4

comprehensive deformation

Answer 4

when comprehensive forces are exerted

Question 5

force extension graph

Answer 5

in the linear region the spring undergoes elastic deformation meaning the spring will return to its original length. however when the gradient falls, this is plastic deformation.

Question 6

force constant K

Answer 6

for a spring obeying hookes law, the applied force F is directly proportional to the extension.

F = KX

Question 7

what does k represent

Answer 7

the stiffness of the spring
the larger the force constant the harder it is to extend
can be determined by the gradient of the graph

Question 8

how to improve accuracy of practical

Answer 8

using a set square
taking readings at eye level to reduce parallax errors

Question 9

work done

Answer 9

work done = force x extension
area under force extension graph
epe

Question 10

elastic potential energy

Answer 10

e=1/2fx

Question 11

tensile stress

Answer 11

force/cross-sectional area

Question 12

tensile strain

Answer 12

extension/original length

Question 13

young modulus

Answer 13

ratio of stress to strain

young modulus = tensile stress/tensile strength

Question 14

diameter

Answer 14

can be measured using a micrometer

Question 15

cross-sectional area can be calculated by:

Answer 15

A=pi x d^2/4

Question 16

polymetric materials

Answer 16

materials that consist of long molecular chains
they behave differently depending on their molecular structure and temperature