Two words, mechanical advantage.
Unable is a synonym for can't or can not. Example: "I am unable to lift the stone." is the same as "I can't lift the stone."
stone
The Egyptians.
people
It is easier to lift a heavy stone under water because the water provides buoyant force that counters the weight of the stone. This buoyant force reduces the effective weight of the stone when submerged in water, making it easier to lift. In air, there is no buoyant force to counteract the weight of the stone, so it feels heavier to lift.
Mayans and the ancient Egyptians
Why was it
Slaves
Theseus
arthur
sphinx
The Rosetta Stone