Gravitation Explained: What It Covers
Newton's Universal Law of Gravitation describes the attractive force between any two objects with mass. It explains phenomena directly related to this gravitational attraction.
Analyzing Phenomena vs. Gravitation
Let's examine each option:
- Formation of tides: This is caused by the gravitational pull of the Moon and the Sun on Earth's oceans. This phenomenon is explained by the Universal Law of Gravitation.
- Weight of objects on Earth: An object's weight is the force of gravity exerted by the Earth on that object. This phenomenon is explained by the Universal Law of Gravitation.
- Resistance offered by air to a moving object: This is known as air resistance or drag. It's a type of frictional force that opposes motion through the air and depends on factors like speed, shape, and air density. This force is not directly explained by the Universal Law of Gravitation.
- Falling of apples from a tree: This is a classic example of gravitational attraction, where the Earth pulls the apple towards it. This phenomenon is explained by the Universal Law of Gravitation.
Therefore, the Universal Law of Gravitation does not explain air resistance.
Important Questions from Gravitation
Which one of the following statement is true for the relation, \(F= \frac{{G{m_1}{m_2}}}{{{r^2}}}\) ?
(All symbols have their usual meanings)Suppose there are two planets, 1 and 2, having the same density but their radii are R 1and R 2respectively, where R 1> R 2. The accelerations due to gravity on the surface of these planets are related as
LIGO stands for
If radius of the earth were to shrink by 1%, its mass remains the same, g would decrease by nearly
The radius of the Moon is about one-fourth that of the Earth and acceleration due to gravity on the moon is about one-sixth that on the earth. From this, we can conclude that the ratio of the mass of earth to the mass of the moon is about
