Hi reader ,

The mass of 10 kg is suspended from the free end of a string, which produces an extension of (Let x m), in the springs length from the normal position.

he spring complete 100 oscillation within 300 seconds, so the time period for one oscillation is equal to 3 seconds. So, the angular frequency is equal to 2π/3 Hz.

Time period= 2π×√m/k, where m = 10kg and Time=3 second. So, the value of k= 44.4

Hope it helps!!