Biodegradable when wood rots
like if you leave types of paper and wood or cardboard over time it will break down and enrich the soil.
same things with a compost.
The correct option is A) work.
Work is said to be done by a force when a force is exerted on an object and the the object on which the force is exerted moves in the direction of the force.
The amount of work done is given by the product of the force and the displacement made by the object.
Option (B) is incorrect, since Watt is the unit of power.
Option (C) is wrong, since joule is the unit of work or energy.
Option (D) is wrong, since power is the rate at which work is done.
Bohrs atomic model only explains the atomic structure in which electrons travel around the nucleus in well-defined orbits determined by quantum conditions. A transition from a higher orbit to a lower orbit will release quantized energies of light, which would explain the light spectrum emitted by an element.
Rolling friction is the resistance to motion experienced by a body when it rolls upon another. It is much less than sliding friction for same pair of bodies. When one body rolls upon another, there is theoretically no sliding or slip between them. And if both are perfectly rigid, there is no surface of contact.