Question

Raw and boiled eggs are made to spin on a smooth table by applying the same torque. The eggs that spin faster is:
(A) Raw egg
(B) Boiled egg
(C) Both will have same spin rate
(D) Difficult to predict

Answer 1

Hint: We will use newton’s first law of motion. It states that an object in motion remains in motion, unless acted upon by an external force. In simple words, if something is moving, it will keep moving unless a force stops it.

Complete step by step solution
Inside the shell of egg, a hard-boiled egg is solid whereas a raw egg is fluid.
When you spin the raw egg, its center of gravity (or balance point) charges as the fluid inside the egg moves around. The results in a wobbling motion in order to achieve balance.
When the hardboiled egg is spin, the solid center has a fixed center of gravity causing it to move at the same time as the shell. The results in a smooth, balanced spin.
The raw egg keeps spinning after you touch it briefly. The liquid egg inside remains in motion; its inertia is greater than that of the solid interior of the hard-boiled egg. An object’s momentum is its resistance to changing. Its state of motion; roughly “how hard it is to stop”. This is related to Newton's first law of motion.
The friction between the table and egg will slow the egg and eventually stop the spinning. Though the liquid inside the egg keeps moving, it too slows down and stops because of the friction between the hard shell and the table.
Therefore the boiled egg will spin faster
Option (B) is correct.

Note
Keep in mind that higher moments of inertia indicates that more force has to be applied in order to cause a rotation whereas lower moments of inertia means that only low forces are necessary. Masses that are further away from the axis of rotation have the greatest moment of inertia.