Answer:
76.1N
Explanation:
Given parameters:
Mass of the ball = 7.77kg
Unknow:
Weight of balloon = ?
Solution:
Weight is the vertical force applied on a body.
Weight = mass x acceleration due gravity
So;
Weight = mass x acceleration due to gravity
So;
Weight = 7.77 x 9.8 = 76.1N
The components in a circuit don't determine the voltages in it.
The voltages are all determined by the battery or power supply
that energizes the circuit.
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 
All of the above, work is a measurement of energy transfer, in Joules.
Potential energy = Joules
Kinetic energy = Joules
The key thing here is that anything having to do with just energy or energy transfer is measured in joules.