Find the length $l$ of the spring shown in Fig. 1.1. Exclude the loops at both ends from the measurement, and record the answer in Table 1.1.
On Fig. 1.1, add a ruler in the place needed for the student to measure the length $l$ in the laboratory.
Find the reading on the ruler at the bottom of the spring as accurately as possible. On Fig. 1.1, place an X to show the student’s eye position.
State one improvement you could make to the table of results.
Using the grid in Fig. 1.2, draw a graph of $L$ against $l$. Begin both axes at the origin $(0,0)$, and then add the best-fit straight line.
State whether $l$ is directly proportional to $L$. Explain your answer.
Use your graph to find the length $l_0$ of the unstretched spring. Show clearly on the graph how you obtained it.
Using your graph in Fig. 1.2, find the extension $e$ of the spring for a load of $3.6\,\text{N}$.
On the axes in Fig. 1.3, sketch a graph of $L$ against $e$.
The gradient of your graph in Fig. 1.2 is a measure of the spring’s force constant. A larger force constant means the spring is harder to stretch. A second spring has the same unstretched length but a larger force constant. On the same axes, draw a line on Fig. 1.2 to show how the length of this second spring varies as loads are added. Label the line S.