Which of the following is a vector quantity? a. 100 ounces of water b. 30 m down c. 88 mi/s d. 45 gallons in a bucket

B. 30 m down

Explanation:

In physics we have two types of quantities:

- Scalar quantity: it is a quantity which only has a magnitude (e.g: mass and time are scalar quantities, since they only have a magnitude)

- Vector quantity: it is a quantity which has both a magnitude and a direction (e.g: velocity is a vector quantity, since it has a magnitude (the speed) and a direction)

In this problem, we have:

A. 100 ounces of water  --> scalar (this is a volume, which has only a magnitude)

B. 30 m down  --> vector (this is a displacement, which has both a magnitude (30 m) and a direction (down)

C. 88 mi/s  --> scalar (this is a speed, which has only a magnitude)

D. 45 gallons in a bucket --> scalar (this is a volume, which has only a magnitude)

So, the correct option is B.

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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