Astronomy/Gravity — 4 Physics PYQs with Answers | UKPSC PYQ Hub

Question 1

The reason behind circular shape of rain waters falling on ground is–

Accepted Answer

Principle of Surface Tension. Raindrops start to form in a roughly spherical structure due to the surface tension of water. Surface tension is the tendency of liquid surface at rest to shrink into the minimum surface area possible.

Question 2

The universal law of gravitation was propounded by

Accepted Answer

Newton. The universal law of gravitation was introduced by Newton. It states that every object in the universe attracts every other object with a force, which is proportional to the product of their masses and inversely proportional to the square of the distance between them.

Question 3

There is no atmosphere on the moon. It is because-

Accepted Answer

The gravitational force is comparatively small. The presence or absence of atmosphere on a celestial body depends on two things- one is the escape velocity of that body and the other is the temperature of the surface of the body. The gravitational force on the moon is very low, hence the escape velocity of gases is very low, Due to this, the gases get diffused on the surface of the moon. This is the reason why there is no atmosphere on the moon.

Question 4

Which scientist discovered the Universal Law of Gravitation?

Accepted Answer

Newton. The first attempt to give a mathematical formula for gravity was made by Isaac Newton, which was surprisingly correct. He formulated the theory of gravity. Newton's theory was later developed into the theory of relativity by Albert Einstein.