Is lightning ac or dc?

The magnitude of the amount of energy released by burning a fuel source, measured in energy per unit mass, is called its fuel value. note that the fuel value is the negative of the isobaric specific heat of combustion for the fuel. if all the energy obtained from burning 1.23 pounds of butane with a fuel value of 10.85 kcal/g is used to heat 128.0 kg of water at an initial temperature of 18.3 °c, what is the final temperature? note that 1 lb = 453.6 g.

Area around a charged object where the objects can exert a force on another charged objects is an electric

What is the moment of inertia i of this assembly about the axis through which it is pivoted? express the moment of inertia in terms of mr