Question

Take a spring of medium stiffness, about 20cm in length. Fix the upper end of the spring to a rigid support on the lower and attach a scale pan of known mass so that the system hangs vertically. Pull the pan 1-2 cm downwards and release. The pan will oscillates up and down. Measure the time of 20 oscillations with the help of a stop watch and calculate the time period of oscillation of pan. Now place a middle size pebble on the pan, set it in oscillations and determine the time period of oscillations again. Calculate the mass of the pebble using the data obtained from your observation.

Answer 1

Answer:Maximum mass that the scale can read, M = 50 kg

Maximum displacement of the spring = Length of the scale, l = 20 cm = 0.2 m

Time period, T = 0.6 s

Maximum force exerted on the spring, F = Mg

where,g = acceleration due to gravity = 9.8 m/s2

F = 50 × 9.8 = 490 N

∴spring constant, k = F/l = 490/0.2 = 2450 N m-1.

Mass m, is suspended from the balance  

∴Weight of the body = mg = 22.36 × 9.8 = 219.167 N

Hence, the weight of the body is about 219 N.