Lesson 7 – Momentum & Collisions

Stage 2: Board Exam Questions & Answers
Page 1 – Short Answer Questions

This section covers important short answer questions frequently asked in Intermediate board examinations. Answers are written in point-wise format for maximum marks.

---

Q1. Define linear momentum.

Answer:

Linear momentum of a body is defined as the product of its mass and velocity.

p = mv

---

Q2. State the law of conservation of momentum.

Answer:

When no external force acts on a system, the total linear momentum of the system remains constant.

---

Q3. What is collision?

Answer:

A collision is an interaction between two bodies during which they exert large forces on each other for a very short interval of time.

---

Q4. Define coefficient of restitution.

Answer:

The coefficient of restitution is defined as the ratio of relative velocity of separation to relative velocity of approach along the line of collision.

---

Q5. What is an elastic collision?

Answer:

An elastic collision is one in which both momentum and kinetic energy are conserved.

---

Q6. What is a perfectly inelastic collision?

Answer:

A perfectly inelastic collision is one in which the colliding bodies stick together after collision and move with a common velocity.

---

Q7. Why does a gun recoil when a bullet is fired?

Answer:

When the bullet moves forward, the gun moves backward to conserve the total momentum of the system.

---

Q8. Is momentum conserved in an explosion?

Answer:

Yes. Even though kinetic energy increases, the total momentum of the system remains conserved.

---

Q9. What is relative velocity?

Answer:

Relative velocity of one body with respect to another is the difference of their velocities.

---

Q10. Write the condition for maximum loss of kinetic energy.

Answer:

Maximum loss of kinetic energy occurs in a perfectly inelastic collision where e = 0.

---

✔ All answers are board-exam ready
✔ Use definitions + key points for full marks

👉 Next page: Long Answer Questions (5–8 Marks)