Computing young s modulus of copper essay

Purpose:

To study the stress/strain habit of copper wire and estimate the Young’s modulus of copper mineral

Apparatus:

Copper wire s i9000. w. g. 32 regarding 4 meters

G-clamp? one particular

Wooden obstruct? 2

Metre rule? four

Pulley about clamp? 1

Micrometer attach gauge? you

Hanger (0. 01 kg)? 1

Placed mass (0. 05 kg)? 8

Placed mass (0. 1 kg)? 6

Placed mass (0. 2 kg)? 4

Placed mass (0. 5 kg)? 1

White colored label sticker? 1

Safety goggles? 1

Rubber tile? 1

Theory:

When a force F is usually applied to the finish of a line with cross-sectional area A along its length, the tensile pressure =

If the extension in the wire is? l, as well as its original size is lo, the tensile strain =

Under stretchy conditions, a modulus of elasticity of a wire, named the Fresh modulus E, is defined as the ratio of the tensile stress used on a body to the tensile strain created.

where At the is indicated in In m-2 or perhaps Pascal (Pa).

E is actually a constant the moment? l is usually small based on the Hooke’s Regulation which mentioned that the tension applied to any solid is usually proportional for the strain that produces for small pressure.

Therefore , each time a material includes a larger the importance of E, it resists to the elastic deformation strongly and a large tension is required to create a small tension. E is definitely thus a measure of the elastic rigidity of a material.

However , when the extension (deformation) of the line is too huge, beyond proportionate limit, sound will no longer obey Hooke’s rules i. e. E is no longer a constant.

Because the stress further more increases, beyond the elastic limit, the wire has a permanent expansion that the cable is no longer elastic and this undergoes plastic material deformation. Recognized increases speedily as the force around the wire can be further increased. The line elongates and breaks. The tension just before the wire fractures is called the breaking stress.

Procedures:

System of the apparatus

1 . The apparatus was set up within the bench top as proven below

” The cable was strongly clamped simply using a G-clamp so that it does not fall.

” A white labeled sticker was fixed to the copper line to act as being a marker such that it is about 50 centimeter from the pulley.

” A metre secret was fixed alongside the wire while using maker to get measuring the extension.

Performance with the experiment

1 . The hanger was tied to the end in the wire so as to straighten out the kinks in the wire as well as the unstretched length (lo) with the wire from the edges of the wooden hindrances up to the gun was scored.

2 . A micrometer screw gauge was used to measure the diameter with the wire in different aspects for each with the 8 area along the cable.

3. The wire was loaded with placed mass m in

actions of zero. 10kg and then 0. 05kg and the exts? l following each launching were recorded until the wire broke.

Data table:

Unique length of line lo sama dengan (3. 500 ï 0. 001) m

Percentage mistake in lo=

Diameter with the wire (mm)

0. 255

0. two hundred and fifty

0. 225

0. 230

0. 240

0. 255

0. 225

0. 255

Average diameter of the cable = (0. 240 ï 0. 005) mm

Percentage error in d =

Readings intended for the graph:

Load meters / kilogram

0. 10

0. 20

0. 40

0. forty

0. 60

0. 62

0. sixty-five

Extension? t / mm

0. five

1 . zero

1 . five

2 . zero

2 . your five

3. zero

3. 5

Load m / kilogram

0. 70

0. seventy five

0. almost eight

0. eighty five

0. 90

0. ninety five

1 . 00

Extension? l / millimeter

3. a few

4. 0

5. 0

6. 0

6. 5

7. five

Broke

Info analysis:

Young’s modulus

exactly where F may be the tension inside the wire and A is the cross-section region

Since and

From the chart, the slope of the best match line through the points of the perfect line part of the chart

Assume that the cross-sectional place did not fluctuate as the stress increased.

Mistakes & accuracy:

From the chart

the slope of the best fit line:

the utmost slope:

the minimum incline:

Deviations: m+ ” m = 12. 1

Deviations: m ” m- sama dengan 26. zero

The maximum mistake in incline = much larger of the deviations = 21. 0

Incline of load-extension graph = (192. 7 ï twenty six. 0)

Percentage error in slope:

Percentage error in E

= % error in slope + % error in lo + 2? % error in d

Young’s modulus of copper, E = (125 ï 22) GPa

Bottom line:

” The stress applied to a copper cable (s. watts. g. 32) is immediately proportional for the strain that produces before the extension turns into 3. 5mm.

” Precisely stress to strain could possibly get smaller but not constant when the extension over and above 3. 5mm (proportional limit), i. at the. after the expansion reached 3. 5mm, tiny increase in tension can produce a great increase in tension.

” Water piping obeys the Hooke’s regulation.

” The Young’s modulus of birdwatcher is (125 ï 22) GPa

Causes of Error:

1 . The copper wire did not have a constant cross-sectional place along its length.

installment payments on your There was fractional force due to the pulley applying to the wire.

3. Examining error in measuring recognized and the unstretched length.

4. Fluctuation of room temperature might replace the diameter from the wire during the experiment.

five. The line in the fresh set-up was not exactly horizontal that made our dimension of expansion not exact.

6. The cross sectional area of the wire got leaner under stress in order that the expected tension would be below the stress actually applied.

Improvement of the Test:

1 . Set the metre ruler by simply another G-clamp so that way of measuring of the extension can be more accurate.

2 . In order to measure extremely small extension with superior, “optical lever (a looking glass mounted on a small pivot) can be utilised instead of just utilizing a simple m stick.

a few. Repeat the experiment many time and consider average of the extension beliefs so that better result can be obtained

4. The experiment could be repeated because below so the small extendable of the cable can be tested accurately by vernier level; moreover, it will have no extra fractional connaissance due to the presence of pulley.

5. Repeat the test by using copper wire based on a s. w. g and take an average of the Young’s modulus attained so that we are able to estimate the importance of Young’s modulus of copper more accurately.

Safeguards:

1 . Use safety glas?gon during the research so as to protect our sight when the line breaks ultimately

2 . The load should not be too high off the floor, and there should be an appropriate soft landing platform, including runner floor tile right below the load.

a few. The unstretched length needs to be at least 3m intended for the cable to extend.

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