Question

Which of the following is not true for the Universal law of gravitation?
A) It is the gravitational force between the sun and earth, which makes the earth move around the sun.
B) The tides formed in sea are because of gravitational pull exerted by the sun and the moon on the surface of water.
C) It is the gravitational pull of the earth which keeps us and other bodies firmly on the ground.
D) The gravitational force exerted by the sun on earth is larger than that exerted by earth on sun.

Answer 1

Hint: Read the question carefully as it asks for the incorrect option. In order to answer the question you must be aware of the Universal law of gravitation topic. Kindly go through it once. Also remember the units of gravitational constant. Gravitation is nothing but a universal law which is related to interactions between mass particles.

Complete step by step answer:
Universal law of gravitation was given by Sir Isaac Newton in 1687 and it is used to explain the observed motions of the planets and moons. The law states that every particle in the universe attracts every other particle in the universe with a force that is directly proportional to the product of the masses of two particles and inversely proportional to the square of the distance between them.

The earth revolves around the sun and rotates about its axis as well. The spinning of the earth is called rotation. At the same time, the earth is moving around the sun which is due to the gravitational force between them. Else the Earth would travel in a straight line.
Hence Option A is correct.

Gravity is one major force that creates tides. Sir Isaac Newton explained that the gravitational pull of the sun and moon on the ocean of earth results in the wave generation. The tides arising due to the moon are known as lunar tides.
Hence Option B is correct.

Why a ball thrown upwards falls to the ground is because of the gravitational force. Earth's gravity is what keeps us on the ground and what makes things fall. Anything that has mass also has gravity. Objects with more mass have more gravity.
Hence Option C is correct.

The gravitational force exerted by the sun on earth and that exerted by earth on sun is equal. Since gravitational force is force between two objects hence both the bodies exert equal force on each other.
Hence Option D is incorrect.
So the answer to this question is Option D.

Additional Information: The law of universal gravitation helps scientists study planetary orbits. The small perturbations in a planet’s elliptical motion can be easily explained owing to the fact that all objects exert gravitational Influences on each other. Gravity is capable of bending light.

Note: Remember that gravitational force between two bodies have equal magnitude and opposite direction for force exerted on each other. Since gravitational force is inversely proportional to the square of distance between the bodies hence as the distances between the bodies increase the gravitational force becomes weaker.