Question

A scale pan of mass 20g increases the length of a spring balance from 8cm to 10cm.What wil be the lengthof the spring when a 100g mass is added on the pan?​

Answer 1

This is sample answer_______

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/s

2

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=2π

k

m

∴m=(

2π

T

)

2

×k=(

2×3.14

0.6

)

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.