I think the correct answer among the choices listed above is option C. Magnetic levitation has been used to innovate transportation. This innovation is commonly known as maglev. It is a new transportation technology where noncontacting vehicles travel above a guideway by magnetic fields.
To solve this problem we will begin by finding the force on each of the elements. For this it will be necessary to obtain the mass, which can be related to density and volume. Finally, by balancing forces it will be possible to obtain the final value of the maximum mass that can be lifted.
By Newton's second law we have,
Here,
g = Gravitational acceleration
m = mass
At the same time mass can be described as,
Therefore the Force 1 is,
Applying the same concepto but for the second mass we have,
Now by equilibrium we have,
Therefore the maximum mass lift by balloon is 
Answer:
All the observers are correct.
Explanation:
This is simply a problem of reference frames from which the motion of the book is being viewed by the various observers.
From their various reference frames, they are all correct.
Observer A must be in the inertial reference frame.
<em>Observers who can explain the behavior of the book and the car by using the relationship between the sum of the forces and changing velocity are said to be observers in inertial reference frames.</em>
This is clearly shown by what observer A noticed. There was a relative motion between the book and the car as she pointed out, making her to be in an inertial reference frame.
<em>Similarly, observers in inertial reference frames can also explain the changes in velocity of objects by considering the forces exerted on them by other objects.</em>
This is shown by observer B as he is able to notice how the force of the car affects the velocity of the book.
Observer C is actually in a non-inertial reference frame, as newtons law of force motion relationship are no longer observed. This occurs in the non inertial reference frame.
I think the answer is D but i could be wrong
