Exploring Energy ConceptsAn object whose mass is 300 lb

QUESTION:

An object whose mass is \(300 \mathrm{lb}\) experiences changes in its kinetic and potential energies owing to the action of a resultant force R. The work done on the object by the resultant force is \(140 \mathrm{Btu}\). There are no other interactions between the object and its surroundings. If the object's elevation increases by \(100 \mathrm{ft}\) and its final velocity is \(200 \mathrm{ft} / \mathrm{s}\), what is its initial velocity, in \(\mathrm{ft} / \mathrm{s}\) ? Let \(g=32.2 \mathrm{ft} / \mathrm{s}^2\).