3. Charles, whose mass is 65 kg, walks at a constant speed up a flight of stairs 6.0 m in 10 min. What average power is he using? [3A] 4. A 245 g Peregrine falcon sitting on a cliff 500.0 m above the ground, spots a pigeon flying 100 m above the ground. If the falcon drops straight down, how fast will it be flying when it catches the pigeon? [3A] 5. How much electrical energy is used by a 60.0 W light bulb if it was accidentally left on for eight hours? [2A]