General Q&A for Class 12 · Page 175
5,215 free answers in General for Class 12 students, across CBSE, ICSE and State boards.
Question & Answer
Questions
- GeneralClass 12All
How to calculate average speed given 2 speeds?
When traveling equal distances at two different speeds, use the harmonic mean formula: Average Speed = (2 × Speed₁ × Speed₂) ÷ (Speed₁ + Speed₂) For example, if you travel at 40 km/h for half the distance and 60 km/h for the other half, the average speed is (2 × 40 × 60) ÷ (40 + 60) = 4800 ÷ 100 = 48 km/h. Note that this is NOT simply (40 + 60) ÷ 2 = 50 km/h.
- GeneralClass 12All
How do you calculate average speed per hour?
To find average speed per hour (usually expressed as km/h or mph), divide the total distance by the total number of hours: Measure total distance traveled Measure total time in hours (convert minutes to hours if needed) Divide distance by time Example: 240 km in 4 hours = 240 ÷ 4 = 60 km/h
- GeneralClass 12All
What is the difference between average speed and constant speed?
Constant speed means traveling at the same rate throughout the entire journey without speeding up or slowing down. Average speed is the overall rate calculated from total distance and time, even if the actual speed varied during the trip. For example, you might drive at 40 km/h, then 60 km/h, giving an average that differs from any constant speed.
- GeneralClass 12All
What is average speed called?
Average speed is also referred to as mean speed or average velocity magnitude (though technically, velocity includes direction while speed does not). In physics and everyday use, "average speed" is the most common term used to describe the total distance divided by total time.
- GeneralClass 12All
What best defines average speed?
Average speed is the total distance covered divided by the total time taken, regardless of variations in speed during the journey. It represents a single value that describes the overall rate of motion. Unlike instantaneous speed (which measures speed at a specific moment), average speed gives you the big picture of how fast something traveled over an entire trip.
- GeneralClass 12All
How to solve 2 power 30?
2³⁰ = 1,073,741,824 To calculate: Use calculator function for large powers Break down: 2¹⁰ = 1,024, so 2³⁰ = (2¹⁰)³ = 1,024³ Computing: 1,024 × 1,024 × 1,024 ≈ 1.074 billion Powers of 2 are important in computer science (bytes, memory addressing).
- GeneralClass 12All
How to calculate work-in-process?
Work-in-Process (WIP) in manufacturing/accounting: WIP = Beginning WIP + Manufacturing Costs - Cost of Goods Manufactured Components: Direct materials Direct labor Manufacturing overhead Alternatively: WIP = Units Started × Percentage Complete × Cost per Unit
- GeneralClass 12All
How to calculate PF & ESI on salary?
PF (Provident Fund) in India: Employee contribution: 12% of basic salary Employer contribution: 12% (with breakdown to EPF, EPS) ESI (Employee State Insurance): Employee: 0.75% of gross salary Employer: 3.25% of gross salary Applicable if salary ≤ ₹21,000/month Example for ₹20,000 basic: Employee PF: 20,000 × 0.12 = ₹2,400 Employee ESI
- GeneralClass 12All
What is the formula for average speed?
Average speed is calculated by dividing the total distance traveled by the total time taken. The formula is:
- GeneralClass 12All
Which SI unit is N·m?
N·m (newton-meter) is the SI unit of torque or work/energy, not momentum. For torque, it represents rotational force. For work or energy, newton-meters are equivalent to joules (J). This is different from momentum, which is measured in kg·m/s.
- GeneralClass 12All
What are examples of momentum in everyday life?
Common examples include: A bowling ball knocking down pins A moving truck requiring more distance to stop than a car A bullet fired from a gun having enough momentum to penetrate objects Ocean waves carrying momentum that moves objects on the beach A baseball hit by a bat transferring momentum
- GeneralClass 12All
What is momentum in Class 11 physics?
In Class 11 physics, momentum is introduced as a vector quantity defined by p = mv. Students learn about: The law of conservation of momentum Elastic and inelastic collisions The relationship between force, impulse, and momentum Newton's laws of motion in terms of momentum Problem-solving involving momentum calculations This forms the foundation for understanding more advanced concepts in mechanics.
- GeneralClass 12All
How to identify momentum?
You can identify momentum by observing: The mass of the object (heavier objects have potentially more momentum) The velocity (faster objects have more momentum) How difficult it is to stop the object The damage or effect when the object collides with something Objects with high momentum are difficult to stop quickly and can exert significant force in collisions.
- GeneralClass 12All
What generates momentum?
Momentum is generated when a force acts on an object over time, causing it to accelerate from rest or change its existing motion. According to Newton's second law (F = Δp/Δt), applying force creates a change in momentum. The longer the force is applied or the greater the force, the more momentum is generated.
- GeneralClass 12All
Does light have momentum?
Yes, light has momentum despite having no mass. According to quantum mechanics and Einstein's theory of relativity, light carries momentum given by the formula p = E/c, where E is the photon's energy and c is the speed of light. This is why light can exert pressure (radiation pressure) and is the principle behind solar sails for spacecraft.
- GeneralClass 12All
How is momentum measured in physics?
Momentum is measured by calculating the product of mass and velocity. In practice, you measure an object's mass (using a scale) and its velocity (using speedometers, radar, or motion sensors), then multiply these values. In laboratory settings, specialized equipment like motion sensors and high-speed cameras can track momentum changes during collisions.
- GeneralClass 12All
What device is used to measure momentum?
There's no single device that directly measures momentum. Instead, momentum is calculated using: Scales or balances to measure mass Speedometers, radar guns, or motion sensors to measure velocity High-speed cameras with motion analysis software Force plates and timing gates in sports science The measurements are then combined using the formula p = mv.
- 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.