📘 Chapter 2: Kinematics – Exercise Short Questions
Prepared by Muhammad Tayyab, Subject Specialist Physics, Govt Christian High School Daska. Based on PECTAA 2026 syllabus (National Curriculum 2023).
📖 What's Inside: This section covers exercise short questions from Chapter 2 Kinematics including scalar and vector quantities, head-to-tail rule, distance-time and speed-time graphs, free fall acceleration, and uniform speed vs velocity. Each question is presented with a precise answer as per the official PECTAA 2026 Physics curriculum. Perfect for Punjab Boards (Lahore, Gujranwala, Multan, etc.) and all BISE boards across Pakistan.
📚 Related Resources – Chapter 2: Kinematics
📋 Exercise Short Qs
📝 Short Qs
📖 Comprehensive Qs
🔢 Numerical Problems
✅ MCQs
✏️ Constructed Response
Kinematics covers motion, scalars, vectors, and graphical analysis of motion.
📝 Exercise Short Questions & Answers (PECTAA 2026)
2.1 Define scalar and vector quantities.
Answer:
| Scalar Quantity | Vector Quantity |
|---|---|
| A scalar is that physical quantity which can be described completely by its magnitude only. | A vector is that physical quantity which needs magnitude as well as direction to describe it completely. |
| Examples: distance, length, time, speed, energy, temperature. | Examples: displacement, velocity, acceleration, weight, force. |
✅ Scalar: magnitude only. Vector: magnitude and direction.
2.2 Give 5 examples each for scalar and vector quantities.
Answer:
Scalar quantities: distance, length, time, speed, energy, temperature
Vector quantities: displacement, velocity, acceleration, weight, force
✅ Scalar: distance, length, time, speed, energy. Vector: displacement, velocity, acceleration, weight, force.
2.3 State head-to-tail rule for addition of vectors.
Answer: To add a number of vectors, redraw their representative lines such that the head of one line coincides with the tail of the other. The resultant vector is given by a single vector which is directed from the tail of the first vector to the head of the last vector.
Figure: Head-to-Tail Rule for Vector Addition
✅ Head of one touches tail of the next. Resultant from first tail to last head.
2.4 What are distance-time graph and speed-time graph?
Answer:
Distance-time Graph: A distance-time graph shows the relation between distance (S) and time (t) taken by a moving body.
Speed-time Graph: A speed-time graph shows the relationship between speed (v) and time (t) taken by a moving body.
✅ Distance-time: relation between distance and time. Speed-time: relation between speed and time.
2.5 Falling objects near the Earth have the same constant acceleration. Does this imply that a heavier object will fall faster than a lighter object?
Answer: No, a heavier object will not fall faster than a lighter object. According to the equations of motion for freely falling bodies:
- All objects experience the same gravitational acceleration (g = 9.8 ms⁻²) near Earth's surface, regardless of their mass.
- This implies that both heavy and light objects will reach the ground simultaneously in a vacuum (where air resistance is negligible).
✅ No. All objects fall with the same acceleration g = 9.8 ms⁻² (neglecting air resistance).
2.6 The vector quantities are sometimes written in scalar notation (not bold face). How is the direction indicated?
Answer: When vector quantities are written in scalar notation (not boldface), their direction is indicated in the following different ways:
(i) By stating the direction in words: For example, a force of 10 N towards the east or Velocity of 5 ms⁻¹ northward.
(ii) By giving the angle: For example, a displacement of 5 m at 30° from the x-axis.
OR The direction is indicated by a sign (positive or negative) or by an angle or by an arrow head.
✅ Direction indicated by words, angle, sign, or arrow head.
2.7 A body is moving with uniform speed. Will its velocity be uniform? Give reason.
Answer: A body moving with uniform speed may or may not have uniform velocity.
Case I: If the direction of motion of body is changing, its velocity will get changed. For example: A car moving on circular path with constant speed.
Case II: If the direction of motion of body is constant/linear then its speed as well as its velocity will remain constant.
✅ Uniform speed may or may not have uniform velocity (depends on direction).
2.8 Is it possible for a body to have acceleration when moving with: (i) constant velocity (ii) constant speed?
Answer:
(i) For Constant Velocity: No, when a body moves with constant velocity its acceleration becomes equal to zero because acceleration is the rate of change of velocity over time. For example: A car is moving in a straight line with uniform velocity.
(ii) For Constant Speed: Yes, a body can have acceleration while moving with constant speed. For example: A body moving in a circle has acceleration because its direction of motion changes continuously.
✅ Constant velocity: no acceleration. Constant speed: acceleration possible (if direction changes).
📐 Key Concepts – Kinematics
Scalar: Magnitude only (e.g., speed, distance). Vector: Magnitude + Direction (e.g., velocity, displacement).
Head-to-Tail Rule: Resultant vector from tail of first to head of last.
Free Fall Acceleration: \(g = 9.8 \, \text{ms}^{-2}\) (approx. \(10 \, \text{ms}^{-2}\))
💡 Exam Tip:
For short questions, always write precise and to-the-point answers. Use key terms like "scalar", "vector", "head-to-tail rule", "distance-time graph", "speed-time graph", "free fall acceleration", and "uniform speed" as they are commonly tested in exams. These questions follow the PECTAA 2026 pattern and are prepared by Subject Specialist Muhammad Tayyab.
Chapter 1Physical Quantities and Measurements
Chapter 2✨ Kinematics
Chapter 3Dynamics
Chapter 4Turning Effect of Forces
Chapter 5Work and Energy
Chapter 6Mechanical Properties of Matter
Chapter 7Thermal Properties of Matter
Chapter 8Magnetism
Chapter 9Nature of Science
📖 Complete syllabus coverage for Class 9 Physics (PECTAA 2026) – Chapters 1 to 9
Created by Hira Science Academy | Aligned with PECTAA 2026 Syllabus