1. as described by the first law of thermodynamics, the change in internal energy of a system is equal to a. the sum of the heat added and work performed b. the difference between the heat added and work performed c. the product of the pressure and change in volume d. the ratio of the heat added to the work performed 2. a 3.1-mole sample of an ideal gas is gently heated at constant temperature 290 k. the gas expands to 1.5 times its initial volume as its pressure decreases. what is the change in the internal energy of the gas? let the ideal-gas constant r = 8.314 j/(mol • k). a. 0 j b. 1500 j c. 3000 j d. -3000 j just give the answer no long answers

the first one is d

the second is c

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

a. vertically

explanation:

i tried it and took the test

if im wrong then we have different tests