Inside this guide, is where you will find the secrets to the game. Note that they may not be highly obvious at first, but i assure you this guide will help you immensely.

ChoccyLachy

Aims:
Two experiments were performed in separate labs, each with different aims. Experiment 1 aimed to calibrate a semiconducting diode for use as a thermometer using linear graphing, while experiment 2 aimed to investigate the natural elastic properties of a carrot by measuring the spring constant k and in turn, Young’s Modulus.

Background Information:

Semiconducting Diode Experiment (1): semiconducting diodes are sensitive to temperature, in that their ability to conduct electricity is greatly affected by the temperature of the diode. As a result, they are widely used as thermometers, however, to do so they must first be calibrated using a method which compares conductivity to temperature of diode.

Elastic Properties Experiment (2): Natural, biologically originating materials and structures often exhibit multi-functional and useful properties, as they have had vast periods of time to form due to evolution and other natural processes. As the modern world unfolds, a paramount objective and area of curiosity for engineers and scientists alike is to mimic these exquisite materials for use in artificial form.

Minimum measurable temperature change of diode:

As seen by the data displayed in Figure A.2, the smallest increment in voltage that the diode is capable of displaying is 0.001V. Factoring this into the equation of the line, we are able to determine the smallest measurable change in Temperature.

y = -0.002x + 0.6835

= -0.002x + 0.6835

x = (0.001-0.6835)/-0.002

x= 341.25C

for comparison, we sub in a second voltage using 0 for y, which yields x = 0-0.6835/-0.002

x = 341.75C

by comparing these two items (341.75C-341.25C), we can determine the smallest measurable temperature change on this diode to be 0.5C

Elastic Properties Experiment (2):


Total Mass (g)


Force (N)




Average Displacement (m)


Uncertainty (m)

25


0.245


0.004233


0.0006

50


0.49


0.007933


0.000733

75


0.735


0.0125


0.000967

100


0.98


0.0173


0.0007

125


1.225


0.0225


0.000967

150


1.47


0.027733


0.000733

175


1.715


0.032033


0.001467

Figure B.2

Spring Constant; Uncertainty:

As the spring constant is expressed as k = f/x, and figure B 1 displays a linear plot of Force over Displacement, we can ascertain that the gradient of the line of best fit is the Spring Constant.

Considering the equation for the line of best fit: y = 51.471x + 0.0665; the gradient for the line of best fit is ( y2-y1/x2-x1 ), which equals: 51.471 N/m. Uncertainty of the slope = ( Gradient Max – Gradient Min )/2; therefor : 3.953N/m.

Hence, the complete gradient of the slope is 51.471 ± 3.953N/m

Young’s modulus calculation:

Youngs Modulus is a mechanical property of a physical object, that property being its ‘stiffness ‘. The value itself is derived in 𝑘=𝑌𝑤𝑡^3/4𝐿^3, rearranged to form Y = 4kl^3/wt^3.

Calculation (all units are in metric SI) :

(4*51.471)(0.155^3) / (0.0223*0.0177^3) = 6200019.133Pa or 6*10^6Pa Therefor = 6MPa

Warner and Edwards Model:



Figure B 3

Figure B 3 displays the warner and Edwards model for determining Bulk Modulus. Using this model, it can be determined the carrot used in experimentation has cell wall diameter of 5mm, and thickness of 1.6± 0.4 mm (100MPa Modulus of cell wall).


Discussion and Conclusion:

Semiconducting Diode:

Displayed through figures A.1 and A.2, it can be clearly seen the semiconducting diode was calibrated, and displayed a strong negatively linear progression as temperature increased. The smallest temperature change was measured at 0.5C which is precise enough to be of use as a thermometer. The aims of the experiment were successfully achieved, and this semiconducting diode could be used as a thermometer.

Elastic Properties Experiment:

The resulting data collected and subsequently graphed in Fig.B.1 is positively linear and follows a strong trend, as a result calculations on the spring constant, Young’s Modulus and Bulk modulus were made possible, these being: Spring constant: 51.471 ± 3.953N/m; Youngs Modulus: 6MPa; Bulk Modulus: 100MPa (diameter: 5mm, thickness1.6± 0.4 mm ), hence the aims were successfully fulfilled and conclusive.