GK: Class 12 General Q&A · Page 98
3,658 free answers on GK (General) for Class 12 students, across CBSE, ICSE and State boards.
Question & Answer
Questions
- GeneralClass 12All
What is a simple word for momentum?
In everyday language, momentum can be described as "oomph," "force of motion," or "moving power." While these aren't technical terms, they capture the idea of how much motion an object carries. In sports and business, "momentum" is often used metaphorically to mean having an advantage or being on a roll.
- GeneralClass 12All
What is the expression for momentum?
The mathematical expression for momentum is p = mv, where p is momentum, m is mass, and v is velocity. For more complex situations involving changing mass or relativistic speeds (close to the speed of light), modified expressions are used, but p = mv covers most everyday applications.
- GeneralClass 12All
What is the integral of momentum?
The integral of momentum with respect to time represents action in physics, a fundamental quantity in advanced mechanics and quantum theory. Mathematically: ∫p dt. This concept is important in Lagrangian and Hamiltonian mechanics, forming the basis for the principle of least action, which governs the paths objects take through space and time.
- GeneralClass 12All
What is the difference between momentum and inertia?
While related, momentum and inertia are distinct concepts: Inertia is the tendency of an object to resist changes in its state of motion. It depends only on mass and applies to both moving and stationary objects. Momentum is the quantity of motion an object has. It depends on both mass and velocity, so only moving objects have momentum. Simply put: inertia is about resistance to change, while momentum is about the amount of motion.
- GeneralClass 12All
. How to calculate momentum and impulse?
To calculate momentum: Multiply the object's mass by its velocity (p = mv). To calculate impulse: Either multiply force by time (F × Δt) or find the change in momentum (final momentum - initial momentum = Δp). Example: A 1,000 kg car traveling at 20 m/s has momentum = 1,000 × 20 = 20,000 kg·m/s.
- GeneralClass 12All
What are the two types of momentum?
The two main types of momentum are: Linear momentum: The momentum of an object moving in a straight line, calculated as p = mv. Angular momentum: The momentum of a rotating object, which depends on the object's moment of inertia and angular velocity. Both follow conservation laws in closed systems.
- GeneralClass 12All
Which law of motion is related to momentum?
Momentum is directly related to Newton's second law of motion. While commonly written as F = ma, Newton originally expressed it as "the rate of change of momentum is proportional to the applied force," or F = Δp/Δt. Additionally, Newton's third law (action-reaction) is crucial for understanding momentum conservation in collisions and interactions.
- GeneralClass 12All
Does inertia create momentum?
No, inertia doesn't create momentum. Inertia is a property that resists changes in motion, while momentum is created when an object with mass is set in motion. However, inertia does affect momentum objects with greater inertia (more mass) will have greater momentum when moving at the same velocity.
- GeneralClass 12All
What best defines momentum?
<p>Momentum is best defined as the product of an object's mass and velocity, representing its quantity of motion. It measures how much "oomph" a moving object has and how difficult it would be to stop it. The greater an object's momentum, the more force is required to change its motion.</p>
- GeneralClass 12All
Is momentum a vector or scalar quantity?
Momentum is a vector quantity, meaning it has both magnitude and direction. The direction of momentum is the same as the direction of the object's velocity. This is important in collisions and interactions between objects, where the direction of motion matters just as much as the speed
- GeneralClass 12All
What is momentum and impulse?
Momentum is the quantity of motion (p = mv), while impulse is the change in momentum. Impulse is calculated as the force applied to an object multiplied by the time duration: Impulse = F × Δt. According to the impulse-momentum theorem, impulse equals the change in momentum: F × Δt = Δp. This relationship explains why airbags and crumple zones in cars work they increase the time of impact, reducing the force experienced.
- GeneralClass 12All
Does momentum depend on mass?
Yes, momentum depends directly on mass. According to the formula p = mv, momentum is directly proportional to mass. If you double an object's mass while keeping velocity constant, you double its momentum. This is why heavier objects moving at the same speed as lighter objects have greater momentum.
- GeneralClass 12All
What is the formula for momentum?
The formula for momentum is p = mv, where: p represents momentum m represents the mass of the object v represents the velocity of the object This simple equation shows that momentum depends on both how heavy an object is and how fast it's moving.
- GeneralClass 12All
What is the SI unit of momentum?
The SI unit of momentum is kilogram meter per second (kg·m/s). This unit is derived from the formula p = mv, combining the SI unit of mass (kilogram) with the SI unit of velocity (meter per second). There is no special name for this unit it's always expressed as kg·m/s.
- GeneralClass 12All
What is momentum?
Momentum is a fundamental concept in physics that describes the quantity of motion an object possesses. It represents how difficult it is to stop a moving object. An object with greater momentum requires more force to bring it to rest. For example, a heavy truck moving at high speed has much more momentum than a bicycle moving at the same speed, making it harder to stop.
- GeneralClass 12All
What is ρ × g?
ρ × g represents pressure gradient per unit height in fluids: ρ (rho) = fluid density (kg/m³) g = gravitational acceleration (9.8 m/s²) ρg = weight density (N/m³) Used in pressure formulas: P = ρgh (hydrostatic pressure at depth h).
- GeneralClass 12All
What is W/t in circuits?
In electrical circuits, W/t = P (power): W = electrical work or energy (joules) t = time (seconds) P = power (watts) Electrical work: W = VIt (voltage × current × time) Power: P = VI (voltage × current)
- GeneralClass 12All
How to calculate work rate?
Work rate measures how much work is completed per unit time: Work Rate = Total Work ÷ Time For individuals/machines: Rate = 1/time to complete one unit Combined rate = Rate₁ + Rate₂ + ... (when working together) Example: If worker A completes a job in 6 hours, rate = 1/6 job per hour.
- GeneralClass 12All
How do I calculate work rate?
To calculate work rate in employment or productivity: Identify output: Units produced, tasks completed Measure time: Hours, days, or shifts Divide: Work Rate = Output ÷ Time Express: Units per hour, pieces per day, etc. For collaborative work: Combined rate equals sum of individual rates when working together.
- GeneralClass 12All
What is work on physics?
In physics, work is the energy transfer that occurs when a force causes displacement. It's defined mathematically as W = F × d × cos(θ) and measured in joules. Work can be: Positive: Force aids motion (lifting, pushing forward) Negative: Force opposes motion (friction, air resistance) Zero: No displacement or force perpendicular to motion Wo