Suppose you increase your walking speed from 5m/s to 13m/s in a period of 3s what is your acceleration?

2 2/3 m/s²

Explanation:

Acceleration is a measure of change in speed over time. What it means mathematically is the difference between your ending and starting speed divided by the total time between.

Here, our starting speed is 5 m/s and our ending speed is 13 m/s, so our change in speed is 13 m/s - 5 m/s = 8 m/s, and our total time between is 3 s, so that gives us an acceleration of (8 m/s) / (3 s), which is 8/3 m/s², or 2 2/3 m/s²

(A little note: m/s² is just an abbreviation for m/s/s, or "meters per second per second," and you read it as "meters per second squared")

whichever one it is, it's definitely not one that you included on the list you provided.

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