Answer:
gravitational force
electrostatic force
Explanation:
The forces that balloons may exert on each other can be gravitational pull due to the mass of the balloon membrane and the mass of the gas contained in each. This force is inversely proportional to the square of the radial distance between their center of masses.
The Mutual force of gravitational pull that they exert on each other can be given as:

where:
gravitational constant 
are the masses of individual balloons
the radial distance between the center of masses of the balloons.
But when there are charges on the balloons, the electrostatic force comes into act which is governed by Coulomb's law.
Given as:

where:

are the charges on the individual balloons
R = radial distance between the charges.
Answer:
initial magnetic field 1.306 T
Explanation:
We have given area of the conducting loop 
Emf induced = 1.2 volt
Initial magnetic field B = 0.3 T
Time dt = 0.087 sec
We know that induced emf is given by 


So initial magnetic field = 1.606-0.3= 1.306 T
<span>Temperature causes water molecules to move more quickly, because each individual molecule has more energy as it gets hotter (according to Kinetic molecular theory). If you get water hot enough, the molecules move so much that the hydrogen bonds that hold them together start to break and the water becomes a gas ... water vapor. This your answer unless there are choices.</span>