Well first you need to know the formula for the spring force. It’s -1/2k*d
K being the constant
D being the displacement
We can actually find the force on the spring by calculating the weight of the block. It would be mass multiplied by gravity, convert the grams to kilograms first tho.
600/1000 = 0.6kg
0.6kg * 9.8 m/s^2 = 5.88N
Now plug everything into the equation, also convert the centimeters to meters:
1.2/100 = 0.012 meters
5.88 = -1/2k*(0.012)
5.88 = k*(0.006)
We could drop the negative sign because we really just want the magnitude of the spring constant.
K = 980N