demonstrations:egg_spinning_inertia

Egg Spinning Inertia

Materials: ★☆☆ Easy to get from supermarket or hardware store
Difficulty: ★☆☆ Can be easily done by most teenagers
Safety: ★☆☆ Minimal safety procedures required

Categories: Kitchen Chemistry, Motion, Food Science and Nutrition

Alternative titles: Raw vs. Hard-Boiled Egg Spin

Summary

This demonstration uses spinning eggs to show Newton’s First Law of Motion. A raw egg wobbles and briefly continues spinning when touched due to the moving liquid inside, while a hard-boiled egg spins smoothly and stops immediately when touched.

Procedure

  1. Prepare one hard-boiled egg (cooled to room temperature) and one raw egg.
  2. Show both eggs to the class, explaining that one is raw and one is cooked.
  3. Spin both eggs on a table, then briefly touch each one to stop it. The raw egg will start spinning again slightly after being released, while the cooked egg will stop completely.
  4. Ask students to explain the difference using Newton’s First Law of Motion.

Spinning Eggs | Inertia Demo | Science Experiment - Elearnin:


Egg Experiment to Demonstrate Inertia - Veritasium:


📄 Egg Spinning - Science World: https://www.scienceworld.ca/resource/egg-spinning/

Variations

  • Try spinning a soft-boiled egg to see how its motion compares.
  • Use plastic eggs filled with different materials (sand, rice, water) to mimic different internal states.
  • Relate the demo to human balance—how spinning affects the liquid in our inner ears.

Safety Precautions

  • Handle raw eggs carefully to avoid spills.
  • Wash hands after handling raw eggs to prevent salmonella risk.
  • Perform on a smooth, flat surface to avoid breaking the eggs.

Questions to Consider

  • How can you tell which egg is raw and which is hard-boiled? (The raw egg wobbles, the hard-boiled egg spins smoothly.)
  • What happens inside the raw egg when it spins? (The liquid inside shifts, changing its center of gravity.)
  • Why does the raw egg keep spinning after being stopped? (The liquid inside maintains motion due to inertia.)
  • Why does the cooked egg stop completely when touched? (Its solid interior moves with the shell, so friction stops it immediately.)
  • How does this demonstrate Newton’s First Law of Motion? (Objects in motion stay in motion unless acted upon by an outside force; the liquid inside the raw egg resists stopping.)