Mack Hollins on Instagram: "November Challenge: Science Experiments 🧪 Day 20 - Paper Friction Friction - The force that opposes sliding motion between two surfaces that are touching each other. When you interleave the pages of two stacks of sticky notes, they behave like a Chinese finger trap. The harder you pull, the harder the pages get squeezed together, increasing the normal force. The more pages you add, the larger this effect becomes. Did you complete the challenge?"