Isolated neutrons outside the nucleus are unstable. After a typical lifetime of about 15 minutes, they decay into a proton and another particle called a neutrino. Consider a neutron that lives 900 s when at rest relative to an observer. How fast is the neutron moving relative to an observer who measures its life span to be 2070 s

The answer is V = 0.9*C

Explanation:

from the relativity formula we have to:

Δt = γ * Δto

Clearing γ:

γ = Δt/Δto

Replacing values:

γ = 2070 s/900 s = 2.3

γ = 1/((1-(V/C)^2)^1/2)

1/((1-(V/C)^2)^1/2) = 2.3

1/(1-(V/C)^2) = 2.3^2

1/(1-(V/C)^2) = 5.29

Clearing V:

V = C * ((1 - (1/5.29))^1/2) = 0.9*C

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