When vapor pressure equals atmospheric pressure, it's called boiling point of that liquid.
To solve this problem we will apply the concepts related to the intensity included as the power transferred per unit area, where the area is the perpendicular plane in the direction of energy propagation.
Since the propagation occurs in an area of spherical figure we will have to


Replacing with the given power of the Bulb of 100W and the radius of 2.5m we have that


The relation between intensity I and 

Here,
= Permeability constant
c = Speed of light
Rearranging for the Maximum Energy and substituting we have then,




Finally the maximum magnetic field is given as the change in the Energy per light speed, that is,



Therefore the maximum value of the magnetic field is 
Kinetic Energy,K.E=1/2MV²
mass,m=16kg
velocity,v=4m/s
K.E=1/2×16×4²
=128kgm²/s²
=128 Joules
So simply it to 120m/m for 120 minutes. So then you multiply 120x120 and that equals 14,400
Any force of 29.4 Newtons or greater can do it.