Question

A pointer attached to a spring balance points to 21.5 cm on a scale when no weight is suspended from it. When a mass of 165g is hanged from it, it points 38.0 cm.

1. Determine its spring constant.   
2. What would be the extension if two similar springs A and B in (a) above are used as shown below. 
   

Answer 1

1. e=38.0−21.5=16.5m=0.165m
   k=  1.65N        =10Nm−1
        0.165m
2. K2= 10×10  5N/M
           10+10
   ∴et= F   = 1.65N
           KT    5N/M
   =0.33m
   OR
   e=2×0.165m
   =0.33m