Momentum MCQs Quiz | Class 9
Test your understanding of Class IX Science (Code 086) Unit III: Motion, Force and Work. This quiz specifically covers the topic of Momentum, including its definition, the formula p = mv, SI units, and qualitative applications in real-life scenarios. Attempt these 10 multiple-choice questions to check your preparation level, view your score instantly, and download the full solution PDF.
Understanding Momentum
Momentum is a fundamental concept in physics, often described as “mass in motion.” It is a vector quantity that depends on both the mass of an object and the velocity at which it is moving. Understanding momentum is crucial for analyzing collisions and the forces required to stop or start moving objects.
Key Concepts & Formula
- Definition: Momentum is defined as the product of the mass of an object and its velocity.
- Formula: p = m v
Where p is momentum, m is mass, and v is velocity. - SI Unit: The standard unit is kilogram-meter per second (kg m/s).
- Nature: It is a vector quantity. Its direction is the same as the direction of the velocity vector.
Qualitative Applications
Momentum helps explain many daily phenomena. For example, catching a fast-moving cricket ball requires a player to pull their hands backward. This action increases the time taken to stop the ball, thereby reducing the rate of change of momentum and the force exerted on the hands. Similarly, seatbelts and airbags in cars are designed to increase the time of impact during a collision, reducing the force felt by passengers.
Comparison Table
| Factor | Effect on Momentum |
|---|---|
| Increase Mass | Momentum Increases (Directly Proportional) |
| Increase Velocity | Momentum Increases (Directly Proportional) |
| Zero Velocity | Momentum is Zero |
Extra Practice Questions
- What is the momentum of a body of mass 5 kg moving with a velocity of 2 m/s? (Ans: 10 kg m/s)
- If the velocity of a body is doubled, how does its momentum change? (Ans: It doubles)
- Can a light body have the same momentum as a heavy body? (Ans: Yes, if the light body has a much higher velocity)
- Is momentum conserved in a collision? (Ans: Yes, in an isolated system)
- Why is it harder to stop a loaded truck than an empty one at the same speed? (Ans: The loaded truck has greater mass and thus greater momentum)
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