Forces, movement, shape and momentum

A student investigates how the extension of an elastomeric polymer cord varies with applied force.

Name three pieces of laboratory apparatus that the student needs to carry out this investigation.

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For this investigation, identify which variable is:

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Describe how the student can determine the extension of the polymer cord when a force of $N24\text{ N}$ is applied.

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The student obtains the following data during loading (adding weights) and unloading (removing weights):

(mm)2470.02061.01647.01232.0818.048.000.0\begin{array}{|c|c|} \hline \textbf{Force (N)} & \textbf{Loading Extension (mm)} \\ \hline 0 & 0.0 \\ \hline 4 & 5.0 \\ \hline 8 & 12.0 \\ \hline 12 & 22.0 \\ \hline 16 & 35.0 \\ \hline 20 & 51.0 \\ \hline 24 & 70.0 \\ \hline \end{array} \quad \begin{array}{|c|c|} \hline \textbf{Force (N)} & \textbf{Unloading Extension (mm)} \\ \hline 24 & 70.0 \\ \hline 20 & 61.0 \\ \hline 16 & 47.0 \\ \hline 12 & 32.0 \\ \hline 8 & 18.0 \\ \hline 4 & 8.0 \\ \hline 0 & 0.0 \\ \hline \end{array}

Suggest two ways the student could improve the quality of the data collected (other than repeating and averaging).

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The student concludes: "The polymer cord is an elastic material and it obeys Hooke's law."

Discuss whether this conclusion is correct. You should support your argument using data from the tables.

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