How much velocity should a small toy rocket, weighing 10kg, acquire in order to escape the Earth's gravitational field? (Neglect any type of friction with the atmosphere)
Here, by equating the formula for the kinetic energy of the rocket to the gravitational potential energy, the student would realize after deriving the speed, that the its mass vanishes, therefore making the escape speed independent of the mass, and only dependent on known constant: universal gravitational constant, mass and radius of Earth.
v= sqrt(2GM/R)
AG