question_answer

You have a light spring, a metre scale and a known mass. How will you find the time period of oscillation of mass without the use of a clock?

Answer:

                Suspend the known mass m form the spring and note the extension \[l\] of the spring with the metre scale. If k is the force constant of the spring, then in equilibrium                 \[kl=mg\] or \[\frac{m}{k}=\frac{l}{g}\] Time period of the loaded spring, \[T=2\pi \sqrt{\frac{m}{k}}=2\pi \sqrt{\frac{l}{g}}\] So by knowing the value of extension \[l\], time period T can be determined.