The stiffness of a particular spring is 680 n/m. one end of the spring is attached to a wall. when you pull on the other end of the spring and hold it stretched with a steady force of 133 n, the spring elongates to a total length of 57 cm. what was the relaxed length of the spring? (remember to convert to s. i. units.)

37.4 cm

Explanation:

The force that the spring  exterts when stretched is:

Where x_0 is the relaxed length and k = 680 N/m

If a steady force of 133 N is applied when pulling the spring and elonged to a total length of 57 cm, the spring must extert the same force, but in the opposite direction, that is:

Solving for x_0

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

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