an astronaut on an eva has wandered dangerously far away from the shuttle. she has also exhausted all the fuel in her jet pack. how can she get back to the shuttle?

The conservation of the momentum allows to find the result of how the astronaut can return to the spacecraft is:

The momentum is defined as the product of the mass and the velocity of the body, for isolated systems the momentum  is conserved. If we define the system as consisting of the astronaut and the evo propellant, this system is isolated and the internal forces become zero. Let's find the moment in two moments.

Initial instant. Astronaut and thrust together.

        p₀ = 0

Final moment. The astronaut now the thruster in the opposite direction of the ship.

        = m v + M v '

where m is propellant mass and M the astronaut mass.

As the moment is preserved.

       0 = m v + M v ’

      v ’=  

We can see that the astronaut's speed is in the opposite direction to the propeller, that is, in the direction of the ship.

The magnitude of the velocity is given by the relationship between the masses.

In conclusion, using the conservation of the momentun we can find the result of how the astronaut can return to the ship is:

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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