Understanding speed, velocity, and acceleration is one of the most important parts of Class 9 Physics. These concepts are not only exam-oriented but also explain many real-life motions like cars, trains, running athletes, and falling objects.
In this article, you’ll find simple numericals, explained step by step, without heavy formulas or advanced theory. This makes it perfect for exams as well as concept clarity.
Basic Concepts
Speed: How fast an object moves
Velocity: Speed with direction
Acceleration: Rate of change of velocity
Units:
Speed & Velocity → m/s
Acceleration → m/s²
Solved Numericals on Speed
Numerical 1: Finding Speed
A car travels a distance of 120 km in 2 hours. Find its speed.
Step 1: Write the formula
Speed = Distance ÷ Time
Step 2: Substitute values
Speed = 120 ÷ 2
Step 3: Calculate
Speed = 60 km/h
Answer: The speed of the car is 60 km/h.
Numerical 2: Average Speed
A cyclist covers 30 km in 1 hour and 20 km in the next 1 hour. Find the average speed.
Step 1: Total distance
= 30 + 20 = 50 km
Step 2: Total time
= 1 + 1 = 2 hours
Step 3: Average speed
= 50 ÷ 2 = 25 km/h
Answer: Average speed = 25 km/h
Numerical 3: Time Taken
A bus moves at a speed of 40 km/h. How much time will it take to cover 80 km?
Step 1: Formula
Time = Distance ÷ Speed
Step 2: Substitute values
Time = 80 ÷ 40
Step 3: Calculate
Time = 2 hours
Answer: Time taken = 2 hours
Solved Numericals on Velocity
Numerical 4: Understanding Velocity
A car moves 20 m/s eastward. What is its velocity?
Explanation:
Velocity includes both speed and direction.
Answer: Velocity = 20 m/s eastward
Numerical 5: Change in Velocity
A train changes its velocity from 10 m/s to 30 m/s in the same direction. Find the change in velocity.
Step 1: Formula
Change in velocity = Final velocity − Initial velocity
Step 2: Substitute values
= 30 − 10
Step 3: Calculate
= 20 m/s
Answer: Change in velocity = 20 m/s
Solved Numericals on Acceleration
Numerical 6: Calculating Acceleration
A bike increases its speed from 5 m/s to 25 m/s in 4 seconds. Find its acceleration.
Step 1: Formula
Acceleration = Change in velocity ÷ Time
Step 2: Change in velocity
= 25 − 5 = 20 m/s
Step 3: Calculate acceleration
= 20 ÷ 4 = 5 m/s²
Answer: Acceleration = 5 m/s²
Numerical 7: Uniform Acceleration
A car starts from rest and reaches a speed of 20 m/s in 5 seconds. Find its acceleration.
Step 1: Initial velocity
= 0 m/s
Step 2: Change in velocity
= 20 − 0 = 20 m/s
Step 3: Acceleration
= 20 ÷ 5 = 4 m/s²
Answer: Acceleration = 4 m/s²
Numerical 8: Deceleration (Negative Acceleration)
A moving car slows down from 30 m/s to 10 m/s in 5 seconds. Find its acceleration.
Step 1: Change in velocity
= 10 − 30 = −20 m/s
Step 2: Acceleration
= −20 ÷ 5 = −4 m/s²
Answer: Acceleration = −4 m/s²
(The negative sign shows deceleration.)
Quick Summary Table
| Quantity | Formula | Unit |
|---|---|---|
| Speed | Distance ÷ Time | m/s |
| Velocity | Speed with direction | m/s |
| Acceleration | Change in velocity ÷ Time | m/s² |
Exam Tips (Very Important)
Always write units with answers
Mention the direction when writing the velocity
Show step-by-step working for full marks
Negative acceleration means slowing down
Read the numericals carefully before applying the formulas
Conclusion
These numericals on speed, velocity, and acceleration are designed exactly at the Class 9 exam level, making them easy to understand and quick to revise. Practising such problems improves both concept clarity and scoring ability.
