A child does 0.20 joule of work to compress the spring in a pop-up toy. If the mass of the toy is 0.010 kilogram, what is the maximum vertical height that the toy can reach after the spring is released? What was the velocity of the pop-up toy as it left the ground?

Explanation:

The stopping voltage (or stopping potential) refers to the voltage difference required to stop electrons from moving between plates and creating a current in the photoelectric experiment. ... The product of the charge on an electron and the stopping voltage gives us the maximum kinetic energy of that ejected electron.When the voltage equals the stopping potential, we know that the KE fo the ejected electrons just equals the potential energy at the collector or… KE = PE hf - φ = qV. This equation is very useful. For light shining on the metal, there is a minimum “cutoff” frequency before the ejected electrons have any KE.