Answer: 480 kJ
Explanation: Energy = power · time
E = Pt = 4000 W · 120 s = 480 000 J
A magnetic field is actually generated by a moving current (or moving electric charge specifically). The magnetic field generated by a moving current can be found by using the right hand rule, point your right thumb in the direction of current flow, then the wrap of your fingers will tell you what direction the magnetic field is. In the case of current traveling up a wire, the magnetic field generated will encircle the wire. Similarly electromagnets work by having a wire coil, and causing current to spin in a circle, generating a magnetic field perpendicular to the current flow (again right hand rule).
So if you were to take a permenant magnet and cut a hole in it then string a straight wire through it... my guess is nothing too interesting would happen. The two different magnetic fields might ineteract in a peculiar way, but nothing too fascinating, perhaps if you give me more context as to what you might think would happen or what made you come up with this question I could help.
Source: Bachelor's degree in Physics.
- Initial velocity,u = -2 m/s
- Final velocity,v = -10 m/s
- Time taken, t = 4 seconds
Find the acceleration ( a ) .
We know that,
Substituting the values in the above formula, we get
Hence,the acceleration of a body is -2 m/s².
