Two beetles are walking in the same direction on the straight edge of a large greenhouse roof. Beetle 1 (leader) pauses, while Beetle 2 (follower) keeps moving at 0.075 m/s: Beetle 2 needs to slow down to avoid bumping into Beetle 1’s rear end. Beetle 2 starts slowing down (att= 0)when it is 0.255 m behind Beetle 1. Beetle 2 will eventually stop, without bumping into its friend. (a)What is the least average acceleration that Beetle 2 would have to apply to stop just behindBeetle 1, without accidentally climbing on it? (b)Actually, the prudent Beetle 2 applies twice that minimum acceleration: how far does it actually stop from Beetle 1?

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