In a vacuum, yes, solid and hollow objects of the same mass fall at the same speed.
* Gravity: The force of gravity pulls on all objects with the same acceleration (approximately 9.8 m/s² near the Earth's surface). This means that regardless of shape or density, all objects fall at the same rate in a vacuum.
* Galileo's Experiment: The famous thought experiment (and later, real experiment) by Galileo Galilei demonstrated this principle. He argued that a feather and a cannonball would fall at the same rate in a vacuum, even though they have very different densities and shapes.
However, in air, things are different.
* Air Resistance: Air resistance is a force that opposes the motion of objects through the air. This force depends on the object's shape, size, and speed.
* Hollow vs. Solid: A hollow object will generally have a larger surface area than a solid object of the same mass. This larger surface area means it experiences more air resistance, slowing it down.
Example: A hollow ball will fall slower than a solid ball of the same mass because the hollow ball will experience more air resistance.
In summary:
* Vacuum: Same speed.
* Air: Hollow objects usually fall slower due to greater air resistance.
