Question

Young's Modulus (x1046 psi) 7.68 10.06 10.64 9.91 9.42 8.20 9.08 11.52 9.87 11.04 Group 2 3 4 5 6 7 10 Problem 2. Using the method of least squares, find the straight line equation that represents the stress-strain relation as obtained from your group experiment, with the strain being measured experimentally and stress computed from the theoretical analysis. Draw the curve and discuss the goodness of fit. Problem 3. Using the method of least squares, find the straight line equation that represents the values of elastic modulus as obtained from different group experiments, with the strain being measured experimentally and stress computed from the theoretical analysis. Draw the curve and discuss the goodness of fit

Answer 1

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	Table 1
Group	Youngs Modulus X 10^6			Y=8.7553+0.1794X
X	Y	XY	X^2	Y Estimated
1	7.68	7.68	1	8.9347
2	10.06	20.12	4	9.1141
3	10.64	31.92	9	9.2935
4	9.91	39.64	16	9.4729
5	9.42	47.1	25	9.6523
6	8.2	49.2	36	9.8317
7	9.08	63.56	49	10.0111
8	11.52	92.16	64	10.1905
9	9.87	88.83	81	10.3699
10	11.04	110.4	100	10.5493
55	97.42	550.61	385

	Table 2
		Y=8.7553+0.1794X
Group	Original Stress	Estimated Stress
1	7.68	8.9347
2	10.06	9.1141
3	10.64	9.2935
4	9.91	9.4729
5	9.42	9.6523
6	8.2	9.8317
7	9.08	10.0111
8	11.52	10.1905
9	9.87	10.3699
10	11.04	10.5493

14 12 10 Original stress Estimated Stress 4 10 12

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