VELOCITY
│
├── Definition
│ ├── Rate of change of displacement
│ ├── Vector quantity
│ ├── Has magnitude + direction
│ └── SI Unit = m/s
│
├── Average Velocity
│ │
│ ├── Formula
│ │ └── v = Δr / Δt
│ │
│ ├── Component Form
│ │ ├── v = (Δx/Δt)i + (Δy/Δt)j
│ │ ├── i → x-axis unit vector
│ │ └── j → y-axis unit vector
│ │
│ ├── Direction
│ │ └── Same as displacement
│ │
│ └── Depends On
│ ├── Initial position
│ └── Final position
│
├── Instantaneous Velocity
│ │
│ ├── Meaning
│ │ └── Velocity at a particular instant
│ │
│ ├── Formula
│ │ ├── v = lim(Δt→0) (Δr/Δt)
│ │ └── v = dr/dt
│ │
│ ├── Important Concept
│ │ ├── Δt → 0
│ │ ├── Δr → very small
│ │ └── Direction becomes tangent
│ │
│ └── Direction
│ └── Tangential to path
│
├── Component Form of Velocity
│ │
│ ├── Position Vector
│ │ └── r = xi + yj
│ │
│ ├── Velocity Vector
│ │ └── v = (dx/dt)i + (dy/dt)j
│ │
│ ├── x-component
│ │ └── vx = dx/dt
│ │
│ └── y-component
│ └── vy = dy/dt
│
├── Magnitude of Velocity
│ │
│ ├── Formula
│ │ └── v = √(vx² + vy²)
│ │
│ └── Based On
│ └── Pythagoras theorem
│
├── Direction of Velocity
│ │
│ ├── tanθ = vy/vx
│ │
│ └── θ = tan⁻¹(vy/vx)
│
├── Important NEET Points
│ ├── Velocity is vector quantity
│ ├── Average velocity = displacement/time
│ ├── Instantaneous velocity = derivative of displacement
│ ├── Direction is tangent to path
│ ├── vx = dx/dt
│ ├── vy = dy/dt
│ └── v = √(vx² + vy²)
│
└── Example
│
├── Given
│ ├── vx = 3 m/s
│ └── vy = 4 m/s
│
├── Magnitude
│ └── v = 5 m/s
│
└── Direction
└── θ ≈ 53°
![]() |
| Easy Velocity Notes with MCQs and CBSE Class 11 Physics Questions for NEET Preparation - Dr.Sanjaykumar pawar |
Internal Links
Motion in a Straight Line Notes
Scalars and Vectors Class 11
Distance and Displacement Notes
Speed and Velocity Difference
Acceleration Notes Class 11
Projectile Motion Notes
Kinematics Formula Sheet
NEET Physics Important Questions
CBSE Class 11 Physics MCQs
Units and Dimensions Notes
Velocity Notes for NEET Beginners
1. Meaning of Velocity
Velocity tells us how fast an object moves and in which direction it moves.
- Velocity is a vector quantity.
- It has both magnitude and direction.
- SI unit of velocity is m/s.
2. Average Velocity
Average velocity is defined as the ratio of displacement to total time interval.
Where:
- Δr = displacement
- Δt = time interval
Here:
- i = unit vector along x-axis
- j = unit vector along y-axis
3. Direction of Average Velocity
The direction of average velocity is always same as the direction of displacement.
4. Instantaneous Velocity
Instantaneous velocity means velocity at a particular instant of time.
It is obtained when the time interval becomes extremely small.
5. Direction of Instantaneous Velocity
As Δt approaches zero:
- Displacement becomes very small.
- The displacement direction becomes tangent to the path.
6. Component Form of Velocity
If position vector is:
Then velocity becomes:
7. Velocity Components
- vx = velocity along x-axis
- vy = velocity along y-axis
8. Magnitude of Velocity
The magnitude of velocity is:
This formula is based on Pythagoras theorem.
9. Direction of Velocity Vector
The direction of velocity is given by angle θ.
10. Important NEET Points
- Velocity is a vector quantity.
- Average velocity = displacement / time.
- Instantaneous velocity = derivative of displacement.
- Velocity is tangential to the path.
- vx = dx/dt
- vy = dy/dt
- Magnitude = √(vx² + vy²)
- Direction = tan⁻¹(vy/vx)
11. Quick Revision Table
| Quantity | Formula |
|---|---|
| Average Velocity | Δr / Δt |
| Instantaneous Velocity | dr / dt |
| x-component | dx / dt |
| y-component | dy / dt |
| Magnitude | √(vx² + vy²) |
| Direction | tanθ = vy / vx |
12. Simple Example
Given:
- vx = 3 m/s
- vy = 4 m/s
Magnitude:
Direction:
θ ≈ 53°
Therefore, velocity = 5 m/s at 53° to x-axis.
CBSE Class 11 Physics - Velocity Questions & Answers
1. Multiple Choice Questions (MCQs)
Q1. Velocity is a:
- A) Scalar quantity
- B) Vector quantity
- C) Tensor quantity
- D) Dimensionless quantity
Q2. Average velocity is equal to:
- A) Distance / Time
- B) Speed / Time
- C) Displacement / Time
- D) Acceleration / Time
Q3. SI unit of velocity is:
- A) m
- B) m/s
- C) m/s²
- D) km/h
Q4. The direction of instantaneous velocity is:
- A) Perpendicular to path
- B) Tangential to path
- C) Opposite to motion
- D) Random
2. Very Short Answer Questions
Q1. Define velocity.
Q2. Write SI unit of velocity.
Q3. What is instantaneous velocity?
3. Short Answer Questions
Q1. Differentiate between speed and velocity.
| Speed | Velocity |
|---|---|
| Scalar quantity | Vector quantity |
| Distance/time | Displacement/time |
| No direction | Has direction |
Q2. Define average velocity with formula.
Average velocity is displacement divided by total time taken.
4. Long Answer Questions
Q1. Explain average velocity and instantaneous velocity.
Average Velocity
Average velocity is the ratio of displacement to total time interval.
- It is a vector quantity.
- Direction is same as displacement.
Instantaneous Velocity
Velocity at a particular instant is called instantaneous velocity.
Its direction is tangential to the path.
Q2. Derive magnitude of velocity using components.
If velocity components are vx and vy:
This formula is obtained using Pythagoras theorem.
5. Assertion and Reason Questions
Q1.
Assertion (A): Velocity is a vector quantity.
Reason (R): Velocity has magnitude as well as direction.
Q2.
Assertion (A): Average velocity can be zero.
Reason (R): Displacement can be zero.
6. Fill in the Blanks
- Velocity is a __________ quantity.
- SI unit of velocity is __________.
- Average velocity is displacement divided by __________.
- Instantaneous velocity acts along the __________ to the path.
- Velocity along x-axis is represented by __________.
- Vector
- m/s
- Time
- Tangent
- vx
7. Statement Based Questions
Q1.
Statement 1: Velocity depends on displacement.
Statement 2: Speed depends on distance.
Q2.
Statement 1: Velocity can be negative.
Statement 2: Speed can be negative.
8. Match the Columns
| Column A | Column B |
|---|---|
| 1. Velocity | a. Scalar quantity |
| 2. Speed | b. Tangential direction |
| 3. Instantaneous velocity | c. Vector quantity |
| 4. Average velocity | d. Displacement/time |
Answers:
- 1 → c
- 2 → a
- 3 → b
- 4 → d
9. Case Study Questions
A particle moves along a curved path. At point P, its velocity components are:
- vx = 6 m/s
- vy = 8 m/s
Q1. Find magnitude of velocity.
Q2. Find direction of velocity.
Q3. What is direction of instantaneous velocity?
10. Numerical Questions
Q1. A body moves 20 m east in 4 s. Find average velocity.
Q2. If vx = 5 m/s and vy = 12 m/s, find resultant velocity.
11. HOTS Questions
Q1. Can average speed be greater than average velocity?
Q2. Can velocity change even if speed remains constant?

Comments
Post a Comment