The idea that a penny dropped from the top of the Empire State Building can kill someone on the ground has been a popular urban legend for years. But how much truth is there to this claim? Let’s explore the science behind this myth and uncover the reality.
The Myth: A Deadly Falling Penny
The myth suggests that a penny dropped from a great height, such as the Empire State Building, would gather enough speed and force to kill a person on impact. This dramatic tale has captured imaginations, often being cited as a reason to be cautious near tall buildings.
The Truth: A Harmless Coin
In reality, a penny dropped from the Empire State Building would not be deadly. While it might cause a sting or a minor injury if it hit someone, it lacks the mass and aerodynamic properties to become a lethal projectile. Let’s break down the science to understand why.
Terminal Velocity: The Speed Limit for Falling Objects
When objects fall, they accelerate due to gravity until they reach a constant speed known as terminal velocity. Terminal velocity is achieved when the force of gravity pulling the object downwards is balanced by the air resistance pushing upwards.
For a penny, which is small and lightweight, terminal velocity is relatively low. Studies and experiments have shown that a penny’s terminal velocity is around 30-50 miles per hour (48-80 kilometers per hour). This speed is not enough to cause significant harm.
Factors Affecting the Fall
Several factors influence the speed and impact of a falling penny:
- Air Resistance: A penny’s flat shape creates significant air resistance, preventing it from reaching dangerously high speeds.
- Weight: At about 2.5 grams, a penny lacks the mass to cause serious injury upon impact.
- Shape and Orientation: As the penny falls, it tends to tumble and flutter, which further reduces its speed and potential impact force.
Experiments and Evidence
Scientists and educators have conducted various experiments to test this myth. These experiments consistently show that a falling penny, even from a great height, does not have the energy to be lethal. Popular TV shows like MythBusters have also tackled this myth, demonstrating that a penny poses little threat when dropped from high altitudes.
Other Falling Objects
While a penny is harmless, other objects dropped from significant heights can be dangerous. Heavier and more aerodynamic objects, such as bolts or larger coins, can reach higher terminal velocities and cause injuries. Therefore, it is always best to avoid dropping objects from tall buildings to prevent accidents.
The myth that a penny dropped from the Empire State Building can kill someone is just that—a myth. A penny’s low mass, significant air resistance, and resulting low terminal velocity ensure that it poses no serious threat.
While it might cause a minor sting, it lacks the power to be deadly. Understanding the science behind falling objects helps debunk such myths and promotes a more accurate view of how physics works in the real world. So next time you hear this urban legend, you can confidently share the truth: a penny from the sky is harmless.