solution

Because of the action of a resultant force, an object whose mass is 100 lb undergoes a decrease in kinetic energy of 1000 and an increase in potential energy. If the initial velocity of the object is 50 ft/s, determine the final velocity, in ft/s.

An airplane whose mass is 5000 kg is flying with a velocity of 150 m/s at an altitude of 10,000 m, both measured relative to the surface of the earth. The acceleration of gravity can be taken as constant at g 9.78 m/s2 .

(a) Calculate the kinetic and potential energies of the airplane, both in kJ.

(b) If the kinetic energy increased by 10,000 kJ with no change in elevation, what would be the final velocity, in m/s?