Question
Question: What is the difference between gravitation and gravity?...
What is the difference between gravitation and gravity?
Solution
Firstly, you could define both the given terms, that is, gravitation and gravity elaborately. After giving a very clear definition, you could differentiate both the terms under various important points. You could also give the expression of both the forces to have a clear understanding of how different they are from each other.
Complete solution:
In the question, we are asked to differentiate between gravitation and gravity.
Gravitation could be defined as the force acting between any two bodies. Gravitational force is known to be directly proportional to the product of the masses of the two bodies and inversely proportional to the square of the distance between them. Whereas, gravity is the gravitational force between any object and earth in particular.
Gravitation is thus a universal force while gravity is not as it is restricted to earth and some objects under the vicinity of earth’s gravitation.
Gravitational force is a weak force while force due to gravity is strong.
Gravitational force can be given by the following expression,
F=r2Gm1m2
Where, G is the gravitational constant, m1 and m2 are the masses of the two bodies and r is the distance between them.
While gravity as a force could be expressed as,
F=mg
Where, g is the acceleration due to gravity.
The direction of the gravitational force is known to be in the radial direction connecting the two masses, while for the case of gravity the direction is along the line joining the earth’s centre with the centre of the body. The body is said to be attracted towards the centre of the earth under the force of gravity.
When,r=∞, that is, the separation between the bodies is infinite, then the gravitational force becomes zero. But the force of gravity is said to be zero at the centre of the earth.
Thereby, we have differentiated gravitation and gravity under the above points.
Note:
You may have noted certain constants in the above mentioned expressions. For the first relation we have the universal gravitational constant G that is given by,
G=6.67×10−11m3kg−1s−2
Now for the second expression we have acceleration due Earth’s gravity which also taken as a constant and is given by,
g=9.8ms−2