If swimmers had a choice of the water slides shown in this figure,
they would all go home dry, since there is no figure. I'll have to try to
answer this question based on only the words in the text, augmented
only by my training, education, life experience, and human logic.
-- Both slides are frictionless. So no energy is lost as a swimsuit
scrapes along the track, and the swimmer's kinetic energy at the
bottom is equal to the potential energy he had at the top.
-- Both slides start from the same height. So the same swimmer
has the same potential energy at the top of either one, and therefore
the same kinetic energy at the bottom of either one.
-- So the difference in the speeds of two different swimmers
on the slides depends only on the difference in the swimmers'
mass, and is not influenced by the shape or length of the slides
(as long as the slides remain frictionless).
If both swimmers have the same mass, then v₁ = v₂ .
<span>They are balanced. If the forces were not balanced the book would move*. In this example, the downward force of gravity on the book is counterbalanced by the upthrust of the desk. </span>
the answer is A and i hope its right
