2.5 What is the overall change in potential energy, in ft ? lbf and Btu, of an automobile weighing 2500 lbf in a drive from San Diego, CA to Santa Fe, NM? Take g constant.
2.6 An object of mass 1000 kg, initially having a velocity of 100 m/s, decelerates to a final velocity of 20 m/s. What is the change in kinetic energy of the object, in kJ?
2.7 A 30-seat turboprop airliner whose mass is 14,000 kg takes off from an airport and eventually achieves its cruising speed of 620 km/h at an altitude of 10,000 m. For g 5 9.78 m/s2, determine the change in kinetic energy and
the change in gravitational potential energy of the airliner, each in kJ.