Collisions and Forces Quiz

Name:

Date:

📋 Instructions

Read each question carefully and choose the best answer for multiple choice questions. For short answer questions, write your response in complete sentences using proper scientific vocabulary.

🔘 Part 1: Multiple Choice

Circle the letter of the best answer.

1. What happens to the total momentum in a collision between two objects when no external forces act on them?

A) It increases

B) It decreases

C) It remains constant

D) It becomes zero

2. Which unit is used to measure force?

A) Joules (J)

B) Newtons (N)

C) Watts (W)

D) Meters per second (m/s)

3. In an elastic collision, what is conserved?

A) Only momentum

B) Only kinetic energy

C) Both momentum and kinetic energy

D) Neither momentum nor kinetic energy

4. A spring scale is used to measure:

A) Mass

B) Weight

C) Volume

D) Temperature

5. What type of collision occurs when two objects stick together after impact?

A) Elastic collision

B) Inelastic collision

C) Perfectly inelastic collision

D) Momentum collision

✏️ Part 2: Short Answer

Answer each question in complete sentences.

6. Explain what happens to the kinetic energy in a perfectly inelastic collision and where that energy goes.

7. Describe how you would use a force meter (spring scale) to measure the force needed to pull a book across a table at constant speed.

8. A 2 kg ball moving at 4 m/s collides with a stationary 1 kg ball. After the collision, both balls move together. Calculate their combined velocity after collision and explain your reasoning.

9. Compare and contrast elastic and inelastic collisions. Give one real-world example of each type.

10. Explain why it's important to measure forces in scientific experiments and give two examples of situations where force measurement would be necessary.

🔑 Answer Key

Multiple Choice Answers:

1. C) It remains constant

2. B) Newtons (N)

3. C) Both momentum and kinetic energy

4. B) Weight

5. C) Perfectly inelastic collision

Short Answer Answers:

6. In a perfectly inelastic collision, some kinetic energy is lost and converted to other forms of energy such as heat, sound, or deformation energy.

7. Attach the force meter to the book, pull the book at a steady, constant speed across the table, and read the force measurement on the scale while maintaining constant velocity.

8. Using conservation of momentum: (2 kg × 4 m/s) + (1 kg × 0 m/s) = (3 kg × v). Therefore v = 8/3 = 2.67 m/s. The combined velocity is 2.67 m/s.

9. Elastic collisions conserve both momentum and kinetic energy (example: billiard balls). Inelastic collisions conserve momentum but not kinetic energy (example: car crash).

10. Force measurement is important for understanding interactions between objects and predicting motion. Examples: testing bridge strength, measuring rocket thrust, calibrating safety equipment.