Section 4: Kinetic Energy and Speed 1: Write down the formula for kinetic energy. 2: If a car has a mass of 1,500 kg and is traveling at 20m/s calculate its kinetic energy. 3: Explain why speed matters more than mass in determining the damage in a car crash. Section 5: Crumple Zones and Safety 1. What is a crumple zone, and why is it important in car safety? 2: How does increasing the crumple zone length affect the force experienced during a crash?

**Section 4: Kinetic Energy and Speed**<br /><br />1. The formula for kinetic energy is: KE = 1/2 * m * v² , where KE is kinetic energy, m is mass, and v is velocity (speed).<br /><br />2. Here's how to calculate the kinetic energy of the car:<br /> * **Mass (m):** 1500 kg<br /> * **Velocity (v):** 20 m/s<br /> * **Kinetic Energy (KE):** KE = 1/2 * 1500 kg * (20 m/s)² = 300,000 Joules (J)<br /><br />3. Speed matters more than mass in determining the damage in a car crash because kinetic energy is proportional to the *square* of the velocity, while it's directly proportional to mass. This means that doubling the speed *quadruples* the kinetic energy, while doubling the mass only doubles the kinetic energy. In a crash, this kinetic energy is transformed into the work of deformation (damage). Therefore, a small increase in speed can lead to a much larger increase in the energy available for causing damage than a similar increase in mass.<br /><br /><br />**Section 5: Crumple Zones and Safety**<br /><br />1. A crumple zone is a structural part of a vehicle, usually located at the front and rear, designed to deform and crush in a controlled manner during a collision. It's important for car safety because it absorbs some of the kinetic energy of the impact, lengthening the duration of the collision. This reduces the force experienced by the occupants of the vehicle, lessening the severity of injuries.<br /><br />2. Increasing the crumple zone length decreases the force experienced during a crash. This is because the same amount of kinetic energy is dissipated over a longer distance and a longer time. Since force is related to the change in momentum over time (Impulse-Momentum Theorem), a longer time interval for the change in momentum results in a smaller force.<br />