Question

A 1.0 kg mass attached to a spring is pulled back horizontally across a table so that the potential energy of the system is increased from zero to 190 J. Ignoring friction, what is the kinetic energy of the system after the mass is released and has moved to a point where the potential energy has decreased to 55 J?
Incorrect: Your answer is incorrect. J

Answer 1

-- If it's all happening horizontally, then gravity is not involved. 
Only the spring is.

-- If there's no friction, then total energy is conserved.

-- If you put 190J of energy into the spring by moving the mass,
and there's only 55J of potential energy in the spring now, then
the other 135J of energy is in the kinetic energy of the mass and
the moving parts of the spring.