6. A 2,500 kg airplane can accelerate on the runway from rest to 250 mph in 15 seconds. What is the power provided by the engine? Assume that all the energy goes to the plane's kinetic energy. What other energies are neglected in this assumption? 7. A 75W light bulb was inadvertently left on in the attic. It was on for 950 hours, till it burned out. Electricity cost 9 cents per kWh. How much did the wasted electricity cost?