Aclosed system of mass 10 kg undergoes a process during which there is energy transfer by work from the system of 0.147 kj per kg, an elevation decrease of 50 m, and an increase in velocity from 15 m/s to 30 m/s. the specific internal energy decreases by 5 kj/kg and the acceleration of gravity is constant at 9.7 m/s2. determine the heat transfer for the process, in kj.

-50.005 kJ

Explanation:

Given

mass of system =10 kg

work done=0.147 kJ/kg

Change in elevation

initial velocity

Final Velocity

Specific internal Energy

from first Law of thermodynamics

where KE= kinetic energy

PE=potential energy

U=internal Energy

Q=1.47+3.375-4.850-50

Q=-50.005 kJ

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