A Cessna Citation II jet (call number 90-RC) has a lift-off velocity of 260 km/hr. The runway that 90-RC takes off from is 1200 m long. (a) What is the minimum acceleration that the jet has to have in order to take off before it reaches the end of the runway? (b) How long does it take for 90-RC to take off? (c) 20 s into the takeoff, a fault occurs in one of the engines. From this point on, what acceleration does the jet need in order to stop before it reaches the end of the runway?

d) the number of neutrons plus the number of protons

this could be newton#'s law of cooling. the cooling curve is exponential

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