A student carries out an experiment with a simple pendulum to determine the acceleration of free fall ggg.
To find the length of the pendulum, the student uses a meter rule to measure the distance from the bottom of the support clamp to the top of the spherical bob as x=58.8 cmx = 58.8\text{ cm}x=58.8 cm. Using a calliper, the student measures the diameter of the bob to be d=2.4 cmd = 2.4\text{ cm}d=2.4 cm.
Calculate the length lll of the pendulum to the center of the bob in centimeters.
Explain briefly how the student avoids a parallax (line of sight) error when measuring the distance xxx with the meter rule.
The student displaces the pendulum bob slightly and releases it to swing. The time ttt taken for 25 complete oscillations is 38.6 s38.6\text{ s}38.6 s.
Calculate the period TTT of the pendulum.
Suggest one practical reason why measuring the time for 150 oscillations, rather than 25 oscillations, may not be suitable.
Calculate T2T^2T2.
Calculate the acceleration of free fall ggg using the equation:
g=4π2lT2 g = \frac{4\pi^2 l}{T^2} g=T24π2lwhere lll is in meters. Give your answer to a suitable number of significant figures.
The textbook value of the acceleration of free fall is 9.8 m/s29.8\text{ m/s}^29.8 m/s2. Suggest a practical reason why the result obtained from this experiment may be different.
Suggest two improvements to the experiment.
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.