Outline a practical experiment to investigate the relationship between the displacement of a pendulum bob and its vertical height, and to determine the period of oscillation.

• Setup: Fix the drawing paper vertically on the drawing board using clamps. Suspend the pendulum bob so it hangs freely in front of the paper.
• Rest Position: Draw a line RP representing the rest position of the pendulum string. Mark point P at the center of the bob when it's at rest.
• Displacement: Displace the pendulum bob to one side (P').
• Measurements: Measure the perpendicular distance, $d$, from P' to the line RP. Measure the vertical height, $h$, of P' above P.

Using the measured values of $d$ and $h$ from Step 1, calculate the value of G using the given formula:

Repeat Step 1 and Step 2 for at least four other positions of P', meaning you should vary the displacement of the pendulum bob to obtain different values of $d$ and $h$. Record all your readings in a table. A suitable table format is:

• Oscillation: Remove the drawing board. Set the pendulum bob oscillating through a small amplitude.
• Time Measurement: Use a stopwatch to determine the time, $t$, for 20 complete oscillations.
• Period Calculation: Calculate the period, $T$, of the pendulum using the formula: $$T = \frac{\text{Time for 20 oscillations}}{20}$$

Plot a graph with the calculated values of G on the vertical axis and the corresponding values of h on the horizontal axis.

• Choose appropriate scales for both axes, ensuring they start from the origin (0,0).
• Plot the points (h, G) from your table.
• Draw the best-fit straight line through the plotted points.

From the graph plotted in Step 5, determine the intercept on the vertical (G) axis. This is the value of G where the best-fit line crosses the G-axis (i.e., when $h = 0$).