Inertia Ball

# 1F20.10

Description A havy iron ball is suspended between two identical strings. Break the bottom string by a quick jerk or break the top string by slowly pulling down the bottom string.
Discussion If you pull down the bottom string slowly, the tension in the bottom string is simply F, while the tension in the top string is F + 10N (weight of the iron ball). The top string will break first. When you quickly jerk the bottom string , the tension in the bottom string becomes very large while the tension of the top string remains ~10N since the mass does not accelerate. The bottom string breaks first.
Location 6C