It is called the Coriolis Effect. It is caused by the rotation of the Earth.
The correct answer is
<span>nuclear weak force
</span><span>
In fact, the nuclear strong force has a very limited range of action (approximately below 1-2 femtometers), and its magnitude decays exponentially for larger distances. Only the nuclear weak force is weaker than the nuclear strong force at large distance, while the gravity and the electromagnetic force become dominant for distances > 2 femtometers.</span>
Even though you're sweating and straining at the end of that time, and your arm is trembling and your muscles are screaming, in the sense of the definition of work in Physics, <em>NO</em> work has been done holding those books.
