Use the potential difference measuring device (the purple tool). If you place this device on the canvas it reads the potential at that location. If you click the pencil it will draw an equipotential line. Start at a potential of 60 V (next to the central positive charge) and draw an equipotential line. Now move right and decrease in steps of 10V and draw another equipotential. Make sure to have placed ALL THE CHARGES on the grid before start to display the equipotential lines. Continue to draw an equipotential every 10 V until you hit -40V. The electric field and the electric potential are related by:
AV = EU / AX

a. Calculate the value of the electric field at one of the weakest locations.
b. Calculate the value of the electric field at one of the strongest locations.

a) electrical > light, sound, and thermal< < < <

) the mechanical energy of the firefighter moving.< < < < a) electrical > light, sound, and thermal< < < <

c) both a and b.

i am pretty sure it is c because when people are closer together, they cannot move as freely. picture being in a mostly full elevator, for instance. the people are right next to you, and you can barely move.

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