In an arcade game, a 0.12 kg disk is shot across a frictionless horizontal surface by being compressed against a spring and then released. If the spring has a spring constant of 200 N/m and is compressed from its equilibrium position by 6.0 cm, what is the magnitude of the spring force on the disk at the moment it is released?
Use Hooke’s law :
F = -kx
The minus sign is used to correct for the direction of the force. I took the spring’s compression to the let, therefore it too is minus. This gives the spring forces direction to the right. The mass of the disc was not needed.
Hope this helps.