A child’s toy consists of plastic attached to a spring. The spring is compressed against the ﬂoor a distance of 2.46 cm, and the toy is released. The acceleration of gravity is 9.8 m/s2 . If the toy has a mass of 102 g and rises to a maximum height of 60.1 cm, estimate the force constant of the spring. Answer in units of N/m.

Question

A child’s toy consists of plastic attached to a spring. The spring is compressed against the ﬂoor a distance of 2.46 cm, and the toy is released. The acceleration of gravity is 9.8 m/s2 .  If the toy has a mass of 102 g and rises to a maximum height of 60.1 cm, estimate the force constant of the spring. Answer in units of N/m.
My work:
Spring potential = gravitational potential 
.5 (K)(.0246)^2=.102 (9.8)(57.64)
K=57.616944/3.0258e-4
K=190418.8777