Inelastic Collision Lab Activity: Calculating Energy Loss

📚 Topic Summary

In an inelastic collision, kinetic energy isn't conserved; some of it transforms into other forms of energy like heat, sound, or deformation. A classic example is two cars colliding and crumpling. The total momentum of the system, however, is conserved in both elastic and inelastic collisions, assuming no external forces act on the system. Calculating the energy loss involves comparing the total kinetic energy before and after the collision. This lab activity explores these concepts through calculations and critical thinking.

🧪 Part A: Vocabulary

Match the following terms with their definitions:

1. 1. Kinetic Energy
2. 2. Momentum
3. 3. Inelastic Collision
4. 4. Conservation of Momentum
5. 5. Energy Loss

1. A. A collision where kinetic energy is not conserved.
2. B. The energy of motion.
3. C. Mass in motion; calculated as mass times velocity.
4. D. The principle stating that the total momentum of a closed system remains constant.
5. E. The difference between the initial and final kinetic energies in a collision.

Matching Answers:

• ⚛️ 1 - B
• ⚖️ 2 - C
• 💥 3 - A
• 🔗 4 - D
• 🔥 5 - E

✍️ Part B: Fill in the Blanks

Fill in the blanks in the following paragraph using the words provided below.

In an _______ collision, objects may stick together. The total _______ remains constant if the system is closed. However, the total _______ is reduced because some of it is converted to heat, sound, or deformation. To calculate the _______, you subtract the final kinetic energy from the initial kinetic energy. This difference shows how much energy transformed during the ______.

Word Bank: inelastic, momentum, kinetic energy, collision, energy loss

Answers:

• 🎯 In an inelastic collision, objects may stick together.
• 🚄 The total momentum remains constant if the system is closed.
• ⚡ However, the total kinetic energy is reduced because some of it is converted to heat, sound, or deformation.
• 📉 To calculate the energy loss, you subtract the final kinetic energy from the initial kinetic energy.
• 🚗 This difference shows how much energy transformed during the collision.

🤔 Part C: Critical Thinking

Explain, in your own words, why momentum is conserved in an inelastic collision even when kinetic energy is not. Provide a real-world example to support your explanation.

Answer space provided for student's response. Example Answer:

• 🧠 Momentum conservation is based on Newton's Third Law (action-reaction pairs). In a collision, the forces between the colliding objects are internal to the system. These internal forces don't change the total momentum of the system, regardless of whether the collision is elastic or inelastic. Kinetic energy, however, can be transformed into other forms of energy. For example, when a ball of clay hits the floor and sticks, the kinetic energy is converted into heat and sound, but the total momentum before and after the collision remains the same (assuming the floor is stationary and part of the system).