A cannonball with a mass of 50 kilograms and a golf ball with a mass of 0. 8 kilograms are dropped in a vacuum from a height of 10 meters. Compare the acceleration of each object as they fall.

It's gonna take a huge amount of time and effort, and we're gonna spend a huge amount of money, to build a vacuum chamber big enough to do this experiment.  

So when we're finally ready to try it, the cannonball and golf ball will make a  kind of cute experiment, but let's make it really interesting.  Let's ALSO try it with a feather, an apple, a watermelon, a tennis ball, a basketball, a coffeepot, a chair, an old computer, a set of dishes, a trombone, a bicycle, a math book, a TV set, a gallon of milk, a skateboard, a shotgun, a concrete block, a car, a waterbed, a schoolbus, a battleship, your dog, and my wife !

Drop every single one of them from a height of 10 meters.

Every single one of them accelerates at 9.8 m/s² as it falls, takes 1.429 seconds to reach the floor, and hits the floor at a speed of 14 m/s.  The feather, the schoolbus, and my wife stay together all the way down.

The only way this doesn't happen is if ...

-- you do this experiment in some other place that's not Earth, or

-- you throw one of the objects and you don't just drop it, or

-- the vacuum chamber has a leak and some air gets into it.

Because that's how gravity works.

b would be the answer