GK: Class 12 General Q&A · Page 127
3,658 free answers on GK (General) for Class 12 students, across CBSE, ICSE and State boards.
Question & Answer
Questions
- GeneralClass 12All
What is the gravity class 9 formula?
In Class 9 physics, the basic gravity formula is F = m × g, where F is the force (weight) in Newtons, m is the mass in kilograms, and g is the acceleration due to gravity (9.8 m/s²). This simplified formula helps students understand that an object's weight is its mass multiplied by gravitational acceleration. For universal gravitation, students also learn F = G × (m₁ × m₂) / r².
- GeneralClass 12All
What is the universal law of gravitation?
The universal law of gravitation states that every particle of matter in the universe attracts every other particle with a force directly proportional to the product of their masses and inversely proportional to the suare of the distance between them. Mathematically expressed as F = G × (m₁ × m₂) / r², this law explains why planets orbit stars, why the Moon orbits Earth, and why objects fall to the ground.
- GeneralClass 12All
What's the formula for g force?
The g-force formula is G-force = acceleration / 9.8 m/s². G-force measures acceleration relative to Earth's gravity. For example, if you experience 20 m/s² of acceleration, you're experiencing 20 ÷ 9.8 ≈ 2g. During free fall, you experience 0g, while standing still on Earth's surface subjects you to 1g. G-forces can be calculated in any direction: positive g (head to toe), negative g (toe to head), or lateral g (side to side).
- GeneralClass 12All
What is 1 G-force?
1 G-force euals the normal gravitational acceleration we experience on Earth's surface (9.8 m/s²). When you're standing, sitting, or lying down normally, you're experiencing 1g. This is the baseline force that keeps you grounded. Any increase in acceleration, such as in an accelerating car, elevator, or aircraft, increases the g-force you experience proportionally.
- GeneralClass 12All
Why is it called g-force?
It's called g-force because it's measured as multiples of Earth's gravitational acceleration (g = 9.8 m/s²). The "g" stands for gravity, and the force represents how many times Earth's normal gravity you're experiencing. This naming convention makes it easier to understand extreme accelerations by comparing them to the familiar sensation of Earth's gravity rather than using absolute acceleration values.
- GeneralClass 12All
What is a high G-force?
A high G-force typically refers to accelerations above 5g for sustained periods or above 9g briefly. Fighter pilots regularly experience 7-9g during combat maneuvers, astronauts experience 3-4g during rocket launches, and roller coaster riders might experience 3-5g. Anything above 5g becomes increasingly dangerous without proper training and euipment, as it affects blood flow and can cause loss of consciousness.
- GeneralClass 12All
How does the g formula work?
The g formula g = G × M / r² calculates gravitational acceleration, where G is the gravitational constant, M is the planet's mass, and r is the distance from the planet's center. On Earth's surface, this yields approximately 9.8 m/s². This formula explains why gravity is weaker on the Moon (1.62 m/s²) due to its smaller mass, and why gravity decreases with altitude as distance from Earth's center increases.
- GeneralClass 12All
How to calculate G value?
To calculate the gravitational constant G, scientists use precision experiments like the Cavendish experiment, which measures the gravitational attraction between known masses at known distances. The currently accepted value is G = 6.674 × 10⁻¹¹ N·m²/kg². You can also calculate local g (acceleration due to gravity) using g = G × M / r², where M is Earth's mass and r is the radius including your altitude.
- GeneralClass 12All
How is gravity measured?
Gravity is measured using gravimeters, which are extremely sensitive instruments that detect variations in gravitational acceleration. Absolute gravimeters measure g directly by timing free-falling objects in a vacuum, while relative gravimeters measure differences in gravity between locations. Scientists also use satellite gravity mapping to measure Earth's gravitational field from space. Simple measurements can be made using pendulums or by timing falling objects.
- GeneralClass 12All
What is the range of gravity?
Gravity has infinite range, meaning its effect extends throughout the entire universe, though it weakens with distance according to the inverse suare law. While gravity from Earth is strongest at the surface, it never truly reaches zero it just becomes negligibly small at great distances. The Moon experiences Earth's gravity from 384,400 km away, and our Sun's gravity influences objects in the Oort Cloud nearly a light-year away.
- GeneralClass 12All
How to calculate g force in kg?
To calculate g-force in terms of weight, use Force (kg-force) = mass (kg) × g-force. For a 70 kg person experiencing 3g, the effective weight is 70 × 3 = 210 kg-force. However, note that kg-force isn't a standard SI unit the proper unit is Newtons (N = kg × m/s²). So, 70 kg at 3g euals 70 × 3 × 9.8 = 2,058 Newtons of force.
- GeneralClass 12All
How much force is 70g?
70g represents 70 times Earth's normal gravity, which euals an acceleration of 686 m/s² (70 × 9.8). This is an extreme force that would be instantly fatal to humans. For a 70 kg person, 70g would create an effective weight of 4,900 kg (nearly 5 metric tons) or about 48,000 Newtons of force. Such forces only occur in extreme impacts like high-speed crashes.
- GeneralClass 12All
What is 100 kg times gravity?
100 kg times gravity (9.8 m/s²) euals 980 Newtons of force. This represents the weight force of a 100 kg object on Earth's surface. In everyday terms, this is approximately 220 pounds of force. This calculation (F = m × g) is fundamental in physics for converting mass to weight and understanding how much force an object exerts due to gravity.
- GeneralClass 12All
What happens to your body during high G-force?
During high g-force, blood is forced away from your brain toward your lower body (during positive g), causing reduced oxygen to the brain. This progresses through stages: gray-out (peripheral vision loss), tunnel vision, blackout (vision loss while conscious), and finally G-LOC (G-force induced loss of consciousness). Your heart must work harder to pump blood upward, organs feel heavier, breathing becomes difficult, and you may experience chest pain. Extreme forces can cause hemorrhaging, bro
- GeneralClass 12All
How do fighter pilots handle G-force?
Fighter pilots handle g-force through specialized G-suits, physical conditioning, and anti-G straining maneuvers (AGSM). G-suits are pressure garments that inflate around the legs and abdomen during high-g maneuvers, preventing blood from pooling in the lower body. Pilots also perform the "hook maneuver" tensing leg and core muscles while controlling breathing—to maintain blood pressure in the brain. Extensive training builds tolerance and teaches recognition of early warning signs like
- GeneralClass 12All
What is the highest g force ever recorded?
The highest g-force survived by a human is approximately 214g by race car driver Kenny Bräck in 2003 during a crash at Texas Motor Speedway. However, this was for a fraction of a second. For voluntary exposure, Colonel John Stapp endured 46.2g during rocket sled deceleration tests in 1954. These extreme examples involved exceptional safety euipment and very brief exposure times measured in milliseconds.
- GeneralClass 12All
What is the maximum G-force a human can survive?
Humans can survive brief exposures of 40-50g with proper restraints, though this often causes severe injuries. With modern safety euipment and body positioning, race car drivers have survived crashes exceeding 100g for milliseconds. However, sustained forces above 5-6g can cause unconsciousness in untrained individuals. Fighter pilots with G-suits can withstand 9g for short periods. The duration of exposure is critical—forces tolerable for milliseconds
- GeneralClass 12All
How much g force kills you?
Sustained g-forces above 10-15g are typically fatal for unprotected humans, though the exact lethal threshold depends on direction, duration, and individual physiology. Horizontal g-forces (front-to-back) are more tolerable than vertical forces (head-to-toe), which disrupt blood flow to the brain. As little as 4-5g sustained for more than a few seconds can cause blackouts in untrained people, potentially leading to fatal conseuences if operating vehicles or a
- GeneralClass 12All
What is 9.8 gravity in feet?
9.8 m/s² euals approximately 32.2 feet per second suared. This conversion is important in countries using imperial units. It means that in the absence of air resistance, a falling object accelerates by 32.2 feet per second for every second it falls. After 1 second, it's falling at 32.2 ft/s; after 2 seconds, 64.4 ft/s, and so on.
- GeneralClass 12All
Is 70 kg my weight or mass?
When you say "70 kg," you're technically referring to your mass, not your weight. Mass is the amount of matter in your body and remains constant regardless of location. Weight, however, is the force exerted by gravity on your mass and is properly measured in newtons. In everyday conversation, people use "weight" and "mass" interchangeably, but scientifically, your mass is 70 kg, while your weight would be about 686 N on Earth.