what is the value of gravitational constant and its SI unit
The correct answer and explanation is:
Correct Answer:
The value of the gravitational constant is 6.674 × 10⁻¹¹ and its SI unit is m³·kg⁻¹·s⁻².
Explanation:
The gravitational constant, often symbolized by the letter G, is a fundamental physical constant that appears in Newton’s law of universal gravitation. According to this law, every mass in the universe attracts every other mass 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.
Mathematically, Newton’s law is written as:
F = G × (m₁ × m₂) / r²
Where:
- F is the gravitational force
- G is the gravitational constant
- m₁ and m₂ are the two masses involved
- r is the distance between the centers of the two masses
In this equation, the gravitational constant G acts as a proportionality factor. Its value, 6.674 × 10⁻¹¹, is very small. This indicates that the gravitational force is a relatively weak force compared to other fundamental forces like electromagnetism.
The SI unit of G is m³·kg⁻¹·s⁻². This unit is derived from the rearrangement of Newton’s law of gravitation. Force has the unit of newtons (N), which equals kg·m/s². When rearranged to isolate G, the resulting unit becomes m³·kg⁻¹·s⁻².
The gravitational constant is important in various scientific fields including astronomy, physics, and engineering. It allows scientists to calculate the gravitational forces between celestial bodies, the orbits of planets, and the behavior of satellites. It also plays a critical role in Einstein’s general theory of relativity, which extended Newtonian physics to account for phenomena involving very massive objects or high speeds.