An object whose mass is 300 lb experience 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 Btu. There are no other interactions between the object and its surroundings. If the object's elevation increases by 100 ft and its final velocity is 200 ft/s. what is its initial velocity, it ft/s? Let g=32.2 ft/s2.