A physics class is investigating the oscillation of a pendulum.
Describe a precaution which the students might have taken in order to measure the length of the pendulum L L\,L as accurately as possible.
On the students' lab worksheet, they measure the pendulum length on a scale diagram. The measured diagram lengths lll (measured in cm\text{cm}cm) are:
The diagrams are drawn to a scale of 15\displaystyle \frac{1}{5}51.
(i) Record the measured lengths l l\,l in Table 2.1. (ii) Calculate and record the actual lengths L L\,L of the pendulum in Table 2.1.
For each length, the pendulum bob is deflected and released, and the time t t\,t for 20 complete oscillations is measured.
(i) For each value of LLL, calculate the period T T\,T for one complete oscillation using the equation T=t20\displaystyle T = \frac{t}{20}T=20t. (ii) Calculate the values of T2 T^2\,T2 and record them in Table 2.1.
Table 2.1
Experimentl/cmL/cmt/sT/sT2/s2115.62220.10323.68426.82529.80\begin{array}{|c|c|c|c|c|c|} \hline \text{Experiment} & l / \text{cm} & L / \text{cm} & t / \text{s} & T / \text{s} & T^2 / \text{s}^2 \\ \hline 1 & & & 15.62 & & \\ \hline 2 & & & 20.10 & & \\ \hline 3 & & & 23.68 & & \\ \hline 4 & & & 26.82 & & \\ \hline 5 & & & 29.80 & & \\ \hline \end{array}Experiment12345l/cmL/cmt/s15.6220.1023.6826.8229.80T/sT2/s2Plot a graph of T2/s2T^2 / \text{s}^2T2/s2 (yyy-axis) against L/cmL / \text{cm}L/cm (xxx-axis).
Determine the gradient G G\,G of the graph. Show clearly on your graph how you obtained the necessary information.
One of the students wishes to carry out the experiment again to obtain results which are more reliable. Describe one change she might make to the method to achieve this.
164 exam-style questions on CIE IGCSE Physics Physical quantities and measurement techniques, covering Physical quantities and measurement techniques. Each one has a worked solution and a mark scheme showing where the marks go.