A spring balance has a scale that reads from 0 to 50 kg. The length of the scale is 20 cm. A body suspended from this balance, when displaced and released, oscillates with a period of 0.6 s. What is the weight of the body?
Maximum mass that the scale can read, M=50kg Maximum displacement of the spring = Length of the scale, l=20cm=0.2m Time period, T=0.6s Maximum force exerted on the spring, F=Mg where, g= acceleration due to gravity =9.8m/s2 F=50×9.8=490 ∴ Spring constant, k=F/l=490/0.2=2450Nm−1 Mass m, is suspended from the balance. Times period, t=2πkm ∴m=(2πT)2×k=(2×3.140.6)2×2450=22.36kg ∴ Weight of the body =mg=22.36×9.8=219.16N Hence, the weight of the body is about 219 N.
