The impact of a collision at 60mph is how many times greater than at 30mph?

Answer: A — 4 times greater

The correct answer is that the impact of a collision at 60 mph is four times greater than at 30 mph. This can be understood through the relationship between speed and kinetic energy, which is the energy that a vehicle possesses due to its motion. The formula for kinetic energy is \( KE = \frac{1}{2} mv^2 \), where \( m \) is mass and \( v \) is velocity. When comparing the kinetic energy at different speeds, if you increase the speed from 30 mph to 60 mph, you are essentially doubling the speed. Since kinetic energy is proportional to the square of the speed, if you double the speed (from 30 to 60 mph), the new kinetic energy is four times greater (because \( (2v)^2 = 4v^2 \)). Thus, the impact of a collision at 60 mph results in a kinetic energy that is four times that of a collision at 30 mph, making it significantly more dangerous. This understanding emphasizes the importance of driving at safe speeds, as the potential consequences of collisions can escalate dramatically with increased speed.