What is gravitational force? Write its SI unit.
The Correct Answer and Explanation is:
Correct Answer:
Gravitational force is the attractive force that acts between any two objects that have mass.
The SI unit of gravitational force is the newton (N).
Explanation:
Gravitational force is a fundamental force of nature that pulls objects toward each other. It was first described scientifically by Sir Isaac Newton in the 17th century. His law of universal gravitation states that every object in the universe attracts every other object with a force that is directly proportional to the product of their masses and inversely proportional to the square of the distance between their centers. This is expressed by the formula:
F = G × (m₁ × m₂) / r²
In this formula:
- F is the gravitational force between two masses
- G is the gravitational constant (approximately 6.674 × 10⁻¹¹ N·m²/kg²)
- m₁ and m₂ are the masses of the two objects
- r is the distance between the centers of the two objects
The gravitational force acts on all objects that have mass, no matter how small or large. Even though it is the weakest of the four fundamental forces (compared to electromagnetic, strong nuclear, and weak nuclear forces), it is always attractive and has an infinite range. This makes it extremely important in large-scale structures such as planets, stars, galaxies, and the universe itself.
On Earth, gravitational force gives objects weight. For example, when you hold an apple, the force pulling it downward is gravity. That force can be calculated using the formula F = m × g, where g is the acceleration due to gravity on Earth (approximately 9.8 m/s²).
The standard unit used to measure force, including gravitational force, is the newton (N). One newton is the force required to accelerate a one-kilogram mass by one meter per second squared.
