It basically lets the government know you are a citizen of they're country. This lets people carry out many actions in the country, like medical care, taxes, etc etc
Without it, a person would be limited to do things.
Helpful ways: braking - it makes the wheels slow down faster, friction from the chain
harmful: when you fall and slide across the ground, when you get your leg stuck in the chain
B. A sandbar is formed by water. A sand dune is formed by wind.
The statement: “According to Faraday's law, voltage can be changed by moving magnets away from the coil of wire.”, is true. Any type of movements done (away, into or out, toward, rotation, etc.) on the magnetic environment would always generate a voltage. In Faraday’s law, it is clear that there are different ways on how to generate a voltage.