Answer:

Explanation:
From the question we are told that:
Height
Length
Mass 
Final speed
Generally the equation for Potential Energy P.E is mathematically given by

Therefore
Initial potential energy

Generally the equation for Kinetic Energy K.E is mathematically given by

Therefore
Final kinetic energy

Generally the equation for Work_done is mathematically given by

Therefore


<span>If there isn't any force then the normal contact force will be
N=m*g=7.5*9.81=73.58N
which is 73.58-23=50.58N less
so, there the person must pull at 23 degree upward
break down the tension in two components, vertical and horizontal.
vertical tension= 50.58=T*sin23
T=50.58/sin23=129.45N</span>
Destructive interference occurs when path difference = ½-integer
multiple of the wavelength i.e. Minima in diffraction pattern given by,
= ! +
# λ = !1 +
# λ = 3λ/2
m
I think the correct answer would be that because electromagnets are powerful and can be turned off and on anytime. Electromagnet is a magnet in which the magnetic field is made by the electric current that is induced to the system.