Imagine you are on a bus with a helium balloon tied on a string tied to the seat in front of you. the bus stops short to avoid running over a rabbit and you are thrown forward. what happens to the balloon in relation to the bus? 1. the balloon pops. 2. the balloon moves forward. 3. the balloon moves backward. 4. the balloon's position does not change

As the bus accelerates forward, the air inside moves back relative to the bus. The pressure on the back of the bus is higher which will make the balloon floats forward for there is a much lower pressure in front of the bus. Nevertheless, when a short stop happens, the balloon will move backwards due to higher pressure that accumulates in front of the bus. This is an example of general relativity theory where the force you feel when accelerating is indistinguishable from the force of gravity.

electromagnetic shielding is the practice of reducing the electromagnetic field in a space by blocking the field with barriers made of conductive or magnetic materials. shielding is typically applied to enclosures to isolate electrical devices from their surroundings, and to cables to isolate wires from the environment through which the cable runs. electromagnetic shielding that blocks radio frequency electromagnetic radiation is also known as rf shielding.

the shielding can reduce the coupling of radio waves, electromagnetic fields and electrostatic fields. a conductive enclosure used to block electrostatic fields is also known as a faraday cage. the amount of reduction depends very much upon the material used, its thickness, the size of the shielded volume and the frequency of the fields of interest and the size, shape and orientation of apertures in a shield to an incident electromagnetic

from wikipedia

technology is the application of the knowledge gained by science.