Abox is sitting stationary on a ramp that is 42° to the horizontal. the box has a gravitational force of 112.1 n. what is the minimum amount of force that can be applied to the box to get the box to move? 70 n 75 n 80 n 83 n

We should draw a Free Body Diagram of the box here. As the box is sitting on a ramp 42 degrees to the horizontal. It experiences only one force that is the gravitational force (mg) downwards whose value is given to be 112.1 N.

Now if we take components of this force.

We get one component as mg sin (Theta) Sliding Downwards from the ramp slope.

We get another component as mg cos (Theta) into the ramp.

Now to move the box we must apply a force opposite to the mg sin (Theta) component as that is the only movable plane.

So the minimum force will be equal to mg sin (Theta)

= 112.1 * Sin( 42 degrees)

= 75 N approximately ( Answer is B)

momentum of soft ball three times less than baskey ball

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