A ball of 5 kg is moving towards the wall at 6 m/s. After a while, it hits the wall and rebounds back at 4 m/s in the opposite
direction. What is the work done on it?

stands for electromotive force and it is measured in volts. despite its name, it is not actually the force in the sense of being a "pushing" or "pulling" (not measured in newtons).an equation that relates emf,  ℰ,  to a battery's terminal voltage, v, current, i, and internal resistance, r, is    ℰ = v + irin this case, the emf can be interpreted as a voltage—a difference in electric potential.i would not say that it would be considered an energy. if emf can be defined as the energy/work per a unit charge from a battery or other electric source, then it is not strictly energy.

Ibelieve the answer is d. macula  hope my answer has you : )

Supply is the markets term for selling a specific quantity of products at various prices. the law of supply and demand is the one which affect the pricing and also the quantity the market is able to produce or make available.

Sounds propagates through some kind of medium. usually it's air, but it goes just as well through solid objects like walls, windows etc. a soundwave will compress the (air)molecules in front of it, and if this increased density wave hits your ears, you register it as sound. solid objects like walls are a lot denser than air, this means that they will damp a wave, but also carry it easier.