1. Explain how power can be calculated using work and time. Explain how power can be calculated using force, displacement, and time (derive from #1 ). Explain how power can be calculated using force and velocity (derive from #2). What is the SI unit for power and how does it relate to Joules and seconds? Horsepower, hp, is an old-fashion unit for power. How does this relate to Watts? What is the conversion between hp and Watts? A helicopter dangles a rope with a hook tied to the end. The hook is attached to a 650 N load. The helicopter lifts the load up by 12 m in a time of 11 s. What is the power output of the motor in Watts and Horsepower? The power of a light bulb is the amount of electrical energy it consumes in one second. A 40 W bulb, for example, uses 40 J of electrical energy in 1 5. What is the power rating of a light bulb that consumes 4 200 J of electrical energy in 70.0 s