In a vacuum, a heavy object and a light object would hit the ground at the same time. This is because the acceleration due to gravity is constant for all objects, regardless of their mass.

Here's why:

* Gravity's Constant Pull: Gravity exerts the same force on every object, pulling them towards the Earth with the same acceleration.

* Ignoring Air Resistance: In a vacuum, there is no air resistance to slow down the objects.

* Equal Acceleration: Because both objects experience the same acceleration due to gravity, they will fall at the same rate and hit the ground simultaneously.

However, in real-world scenarios, things are different:

* Air Resistance: Air resistance is a significant factor in the real world. Lighter objects experience more air resistance, slowing them down and causing them to fall slower than heavier objects.

* Shape and Surface Area: The shape and surface area of an object also play a role. A feather, for example, will fall much slower than a rock due to its larger surface area and its ability to be affected by air currents.

So, in a vacuum, a heavy object and a light object would hit the ground at the same time. But in the real world, the heavier object would likely hit the ground first due to the effects of air resistance.