HELP! block is released from rest and slides down a frictionless ramp inclined at 30' from the horizontal. When the block reaches the bottom the block-Earth system has mechanical energy Eo The experiment is repeated, but now horizontal and vertical forces of magnitude F are exerted on the block while it slides, as shown above. When the block reaches the bottom, the mechanical energy
of the block-Earth system
A) is greater than Eo
B)is equal to Eo
C)is less than Eo
D)cannot be determined without knowing

A

Explanation:

the horizontal and vertical force acting on it consist a net force on the inclined direction (30degrees below the horizontal) you can tell by the length of the horizontal component (try to see the 30degree incline as horizontal, because that's the direction of the displacement). net work done on the system results in an increase in energy. i hope this can help :D, i'm also taking the ap physics 1 exam tommorow.

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