Materials

Question 1

How do you calculate absolute uncertainty?

Answer 1

half the range in repeats
OR
the precision
(whichever is largest)

Question 2

How do calculate percent uncertainty?

Answer 2

(absolute uncertainty)/(mean value) x 100

Question 3

Define Hooke’s law

Answer 3

the extension of a spring is directly proportional to the applied force up to the limit of proportionality

Question 4

What comes first, the limit of proportionality or the elastic limit?

Answer 4

the limit of proportionality

Question 5

What happens after the limit of proportionality in a F vs ΔL graph?

Answer 5

the line begins to level off

Question 6

What the the area underneath a F vs ΔL graph show?

Answer 6

the elastic potential energy stored

Question 7

What happens to the spring constant if there are two springs in series?

Answer 7

it halves

Question 8

What happens to the spring constant if there are two springs in parallel?

Answer 8

it doubles

Question 9

Which is easier to stretch, two springs in series or two springs in parallel?

Answer 9

two springs in series

Question 10

Define spring constant

Answer 10

the force required to extend a spring 1m

Question 11

Define tensile stress

Answer 11

the tension per unit cross-sectional area of a material

Question 12

Define tensile strain

Answer 12

the extension per unit original length

Question 13

What form must strain be in so that it can be used in a question?

Answer 13

decimal form (NOT as a percent)

Question 14

What does Young’s modulus measure?

Answer 14

the stiffness of a materiel

Question 15

Why do we use Young’s modulus?

Answer 15

It is independent of dimensions

Question 16

What does a large plastic region on a stress-strain graph mean?

Answer 16

the material is ductile

Question 17

What does a little plastic region on a stress-strain graph mean?

Answer 17

the material is brittle

Question 18

How can you find Young’s modulus from a stress-strain graph?

Answer 18

the gradient of the linear region

Question 19

What does the area underneath a stress-strain graph equal?

Answer 19

the energy stored per unit volume

Question 20

How can we find ultimate tensile strength from a stress-strain graph?

Answer 20

the highest point of the graph

Question 21

What do you do to uncertainties when quantities are multiplied or divided?

Answer 21

add the percent uncertainties

Question 22

What do you do to uncertainties when quantities are add or subtracted?

Answer 22

add the absolute uncertainties

Question 23

What is the yield point?

Answer 23

the stress at which a large amount of plastic deformation takes place with a constant or reduced load