Answer
$K=4.03\times 10^6\frac{N}{m}$
Work Step by Step
By law of conservation of energy, elastic potential energy is equal to kinetic energy:
$P.E=K.E$
$\frac{1}{2}K(\Delta y)^2=\frac{1}{2}mv^2$
This simplifies to:
$K=\frac{mv^2}{(\Delta y)^2}$
We plug in the known values to obtain:
$K=\frac{0.170(11.2\times 10^3)^2}{(2.30)^2}=4.03\times 10^6\frac{N}{m}$
