Difference Between Speed and Velocity in Tabular Form with Examples
Difference Between Speed And Velocity is often a source of confusion for JEE Main aspirants. In physics, both relate to how objects move, yet their definitions, formulae, and usage in problems differ. Understanding this difference is crucial for solving kinematics questions, interpreting graphs, and avoiding common conceptual pitfalls. This clarity forms a base for advanced topics like motion in 2D, relative velocity, and uniform versus non-uniform motion.
Speed tells us how fast something is moving, regardless of its direction. Velocity, on the other hand, also considers the direction in which the object is moving. When analyzing motion, using the correct quantity—speed or velocity—directly affects your calculation and the final answer. Many Vedantu resources reinforce this distinction for JEE Main preparations.
Let’s dive into detailed definitions, compare them side by side, see some real-world examples, and learn how this comparison appears in exam questions. Links to advanced topics like motion in 2D dimensions and relative velocity in kinematics are included below for deeper learning.
What Are Speed and Velocity?
Speed is the rate at which an object covers distance. It is a scalar quantity—it has only magnitude and no direction. The formula for average speed is:
Speed (v) = Total distance travelled / Total time taken
Velocity is the rate of change of displacement with time. It is a vector quantity, meaning it has both magnitude and direction. Its formula is:
Velocity (→) = Displacement / Time
Units for both are metre per second (m/s) in SI. However, in exam problems, selecting whether to use speed or velocity depends on whether the question is about distance (path length) or displacement (shortest straight line between starting and ending point).
Learn about displacement and distance comparison at this Vedantu page for greater clarity.
Tabular Comparison: Difference Between Speed And Velocity
| Basis | Speed | Velocity |
|---|---|---|
| Definition | Rate at which distance is covered | Rate of displacement change (with direction) |
| Quantity Type | Scalar | Vector |
| Formula | Distance / Time | Displacement / Time |
| SI Unit | Metre per second (m/s) | Metre per second (m/s) |
| Direction | No direction involved | Has direction |
| Value | Always positive | Can be positive, negative, or zero |
| Example | Car travels 40 km in 1 hr → speed = 40 km/h | Car returns to starting point via different routes → velocity = 0 |
Real-Life Examples: Speed and Velocity in Motion
- A sprinter runs once around a 400 m circular track in 50 s. His speed is 8 m/s, but since he finishes where he started, his velocity is 0 m/s (displacement = 0).
- A bus moves 10 km east in 0.5 hr. Speed = 20 km/h. Velocity = 20 km/h east (since displacement is along the east).
- You walk 3 m north, then 4 m east in 70 s. Total distance = 7 m; displacement is 5 m (by Pythagoras). Average speed = 7/70 = 0.1 m/s. Average velocity = 5/70 ≈ 0.071 m/s northeast.
Common Student Pitfalls: Speed vs Velocity in JEE Main
- Confusing scalar with vector; always check if the question asks for direction.
- For round trips, velocity can be zero, but speed is not.
- For non-straight paths, distance and displacement differ—use correct calculation.
- Ignoring negative sign in velocity when direction reverses along a straight path.
- Units are same (m/s), but meanings are different; SI unit doesn’t imply they are identical quantities.
Study more about displacement, velocity, and acceleration time graphs to master exam-centric applications.
Exam Summary: Key Differences and Revision Notes
- Speed is the magnitude of motion; velocity is magnitude plus direction.
- Speed cannot be negative; velocity can have negative, zero, or positive value.
- Speed uses “distance”; velocity uses “displacement.”
- Both have SI unit m/s, but speed is scalar, velocity is vector.
- In uniform motion, speed and magnitude of velocity can be equal, but often differ if direction changes.
- In circular motion, average velocity over a full round = 0, but speed remains constant.
- Always mention direction when expressing velocity in answers.
Revise with Vedantu’s kinematics revision notes and apply these concepts in JEE Main kinematics mock tests to build confidence.
Before moving to vector algebra, strengthen the basics by reviewing vectors and scalars. To progress, relate speed and velocity to acceleration for solving equations of motion in one or two dimensions.
For more practice, explore Vedantu’s motion in 2d dimensions, average speed formula, and average velocity formula with JEE-solved examples.
This understanding of difference between speed and velocity will help you solve advanced problems and avoid common exam errors. Consistent practice through laws of motion practice papers and referring back to these differences is essential.
FAQs on Speed vs Velocity: Definition, Formula, Examples, and Differences
1. What is the main difference between speed and velocity in physics?
Speed measures how fast an object moves without considering direction, while velocity describes both the speed and the direction of motion.
Main differences include:
- Speed is a scalar quantity (only magnitude).
- Velocity is a vector quantity (magnitude and direction).
- Example: A car driving at 60 km/h north has a velocity, but its speed is 60 km/h only.
2. Is velocity always greater than speed?
No, velocity is not always greater than speed. In fact, velocity can be equal to or less than speed in terms of magnitude.
Key points:
- For straight-line motion in one direction, speed and velocity have the same value.
- For a path with changes in direction, average velocity can be less than average speed.
- Velocity depends on displacement; speed depends on total distance travelled.
3. Can you have speed without velocity?
Yes, you can have speed without a well-defined velocity if the direction is not specified or if the direction changes continuously, as in circular motion.
Examples include:
- A particle moving in a circle always has speed, but its direction (hence velocity) keeps changing.
- Speed is defined for all kinds of motion; velocity requires clear direction.
4. Give three examples to show the difference between speed and velocity.
Examples illustrating speed vs velocity:
- Example 1: If you jog 400 meters around a circular track and return to your starting point in 2 minutes, your speed is 200 m/min, but your velocity is zero (displacement is zero).
- Example 2: Driving 60 km east in 1 hour: Speed = 60 km/h; Velocity = 60 km/h east.
- Example 3: Moving in zig-zag: Speed is total distance divided by time, but velocity is displacement divided by time, which may be smaller.
5. What are the formulas for speed and velocity?
Speed and velocity have different formulas but similar structures.
Basic formulas:
- Speed = Distance / Time
- Velocity = Displacement / Time
6. What is different between speed and velocity?
Speed and velocity differ mainly because speed is a scalar (only size) and velocity is a vector (size and direction).
In short:
- Speed = rate of covering distance, no direction.
- Velocity = rate of covering displacement, includes direction.
- Example: Running in a circle at constant speed, your velocity changes at every point because direction changes.
7. Why is speed called a scalar and velocity a vector? What if the direction changes?
Speed is called a scalar quantity as it has only magnitude and no direction, while velocity is a vector because it includes both magnitude and direction.
When direction changes (like in turning or circular paths), velocity changes, but speed may remain the same. This concept is essential for understanding motion and acceleration.
8. In which situations can an object have zero velocity but nonzero speed?
An object can have zero velocity but nonzero speed if it returns to its starting point or moves in a way where net displacement is zero.
Example:
- Completing a lap on a circular track: you have moved (speed > 0), but your displacement is zero, so your velocity = 0.
9. Do speed and velocity always have the same numerical value?
No, speed and velocity are only equal when the motion is in a straight line and in one direction.
Otherwise:
- Speed can be greater than or equal to magnitude of velocity.
- Speed considers the total path; velocity considers only net displacement.
10. What is the difference between distance and displacement in relation to speed and velocity?
Distance is the total length of the actual path travelled, while displacement is the shortest straight-line change in position.
Relation to speed and velocity:
- Speed uses distance travelled per unit time.
- Velocity uses displacement per unit time.
11. What are the SI units for speed and velocity?
Both speed and velocity have the SI unit metre per second (m/s).
Other units include:
- kilometres per hour (km/h)
- centimetres per second (cm/s)
12. Why are formulas for speed and velocity important for exams like JEE Main?
Understanding the speed and velocity formulas helps solve physics numericals and MCQs in exams like JEE Main and boards.
Why it matters:
- Questions often ask you to distinguish or calculate one or both values.
- Knowing the difference helps avoid common mistakes in direction-based problems.
