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1. (30) Figure 1 is a graph of the change in temperature of a substance as a fun

ID: 1699844 • Letter: 1

Question

1. (30) Figure 1 is a graph of the change in temperature of a substance as a function of the heat added. The process starts at - 30o and ends at 550o C. Assume the substance starts as a solid and ends as a gas, 1 gram of the substance is observed. Note that the graph is truncated on the heat added scale.

http://www.pa.uky.edu/~ellis/phy211/tests211/practicetest3/practicetest3.html

a. [10] Using figure 1, calculate the specific heat of this substance in solid or first phase.




b. [10] What is the Latent Heat of Vaporization for this substance?




c. [10] What is the Specific Heat for this substance in vapor phase?




d. [10] Bone has a young's modulas of about 14.5 x 109 Pa. Under compression it can withstand 160 x106 Pa before breaking. If you estimate the length of your femur (thigh Bone ) to be 0 .5 m calculate the amount of compression this bone can stand.

Explanation / Answer

a) Given that mass m = 1 gm

temperature differnce T   = ( 550C - (-30C )

                                             = 580 C

            Q = m c T

                  c = Q / mT

                     = 815.7 J / 1 gm * c * 580 C

                    = 1.40 J / g C  

b ) latent heat of vapourization is L   = Q / m

                                                             = 3076 J / 1.0 *10^-3 Kg

                                                              = 3076 *10^-3 J / kg

c ) specific heat of vapourization state is  

           Q = m c T

                  c = Q / mT

                     = 5000J / 1 gm * c * 580 C

                    = 8.62 J / g C