A 1.4 kg block oscillates back-and-forth with a period of 4.5 s while it is attached to spring. When the block is instantaneously at rest at the spring’s maximum extension, a 1.1 kg blob of clay is dropped onto the block. How long does the block and clay take to complete one full back-and-forth oscillation now?

measure their densities same density, same sub

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

inverse v=i*r

nice nice

the answer is c. the lower legs are levers, and the knees are fulcrums. the ankles hold the loads.