Answer:k=28.29 kN/m
Explanation:
Given
mass 
height from which Elevator falls 
Let x be the compression in the spring
thus From conservation of Energy Potential energy will convert in to Elastic Potential Energy of spring
----------1
also maximum acceleration is 5g
thus

here 


Substitute x in equation 1





The formula of the kinetic energy is:

where m is a mass of the object, v is speed of the object at the moment of time. So we have:

The answer is
2000 Joules.
Answer:
H = 109.2 TJ.
Explanation:
Please see the attachment below.
<h2>Answer:</h2>
<u>By wrapping the wire along a solenoid and connecting it to electricity</u>
<h2>Explanation:</h2>
If you wrap a copper wire into coils and run an electrical current through it, you will create a magnetic field. If you rotate a permanent magnet as opposed to an item that has been magnetized inside a coil of copper wire, you can create an electrical current. The strength of magnetic field generated is proportional to the amount of current through the winding.