When we fall from a height, our body gains speed due to gravity. The higher we fall from, the faster we're moving when we hit the ground. This sudden stop creates large forces that can injure us.
When we're at height, we have potential energy. As we fall, this potential energy converts to kinetic energy, making us move faster. By the time we reach the ground, all potential energy has become kinetic energy.
Momentum equals mass times velocity. When we hit the ground, our momentum must change from a large value to zero. According to physics, this change requires a force, and the shorter the time, the larger the force becomes.
The impact time determines the force magnitude. Hard surfaces like concrete stop us in milliseconds, creating enormous forces. Soft surfaces like mattresses take longer to stop us, reducing the impact force. This is why falling on hard ground is much more dangerous.
Several factors determine injury severity. Higher falls create more velocity and force. Harder surfaces reduce impact time, increasing force. Smaller contact areas create higher pressure. Protective equipment like helmets and padding can distribute forces and extend impact time, reducing injury risk.