Respuesta :

AL2006
What are the choices ? 

Without some directed choices, I'm, free to make up any
reasonable statement that could be said about Kevin in this
situation.  A few of them might be . . .

-- Kevin will have no trouble getting back in time for dinner.

-- Kevin will have no time to enjoy the scenery along the way.

-- Some simple Physics shows us that Kevin is out of his mind.
He can't really do that.

           -- Speed = (distance covered) / (time to cover the distance) .

If time to cover the distance is zero, then speed is huge (infinite).

           -- Kinetic energy = (1/2) (mass) (speed)² .

If speed is huge (infinite), then kinetic energy is huge squared (even more).
There is not enough energy in the galaxy to push Kevin to that kind of speed.

         -- Mass = (Kevin's rest-mass) / √(1 - v²/c²)

-- As soon as Kevin reaches light-speed, his mass becomes infinite.
-- It takes an infinite amount of energy to push him any faster.
-- If he succeeds somehow, his mass becomes imaginary.
-- At that point, he might as well turn around and go home ...
     if he ever reached Planet-Y, nobody could see him anyway.

Kevin’s weight may change between Planet X and Planet Y.

Mass is the amount of matter contained in an object. Gravity is Earth’s pull of a body towards its center.  

Weight (W) is product of the mass (m) of the object and the force of gravity (g) acting on the object.  

W = mg  

The force of gravity may change between Plant X and Planet Y, and thus Kevin’s weight may change between Planet X and Planet Y.