Velocidad-es una cantidad vectorial física; Tanto la magnitud como la dirección son necesarias para definirlo.
It takes greater force to accelerate an object that has more mass. But the gravitational force between the Earth and an object is greater when the object hass more mass. It works out just right to make any object with any mass accelerate at the same rate.
If you apply a little bit of force, one will move easier than the other since it is lighter.
