Amoving van travels 10km north, then 4 km east, drops off some furniture and then drives 8 km south. (a) sketch the path of the moving van. (2) how far is the van from its starting point? (hint: it is the magnitude of the displacement vector.

4.47 km

Explanation:

Drawing the path of the van we get a shape with two exposed points A and E. If we draw a line from point E perpendicular to AC we get point B. This gives us a right angled triangle AEB.

From Pythagoras theorem

AE² = AB² + EB²

Hence, the van is 4.47 km from its initial point

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