Universal Law of Gravitation

Q.

A body weighs $72N$ on the surface of the earth. What is the gravitational force on it due to the Earth at a height equal to half the radius of earth?

1. $48N$

2. $32N$

3. $30N$

4. $24N$

Q.

Explain what is gravitation?

Q.

Does the force of gravitation exist between two astronauts in space?

Q.

😕🤔❓Earth is Spherical so why we are not falling❓😕🤔(please answer in brief)

Q.

State the energy changes in a gun shot.

Q.

Which law can explain the falling of raindrops and snowfall?

Q.

Gravitational force on the surface of moon is only 1/6 as strong as gravitational force on earth what is the weight in newton of a 120 kg object on the moon and on the earth

Q.

Who discovered gravity?

Q.

Why is it not easy to quantize gravity?

Q.

Imagine a planet is revolving around a very massive star in a circular orbit of radius R with a period of revolution T. If the gravitational force of attraction between the planet and the star is proportional to $R^{\frac{-5}{2}}$, then

1. $T^2$ is proportional to $R^3$

2. $T^2$ is proportional to $R^{\frac{7}{2}}$

3. $T^2$ is proportional to $R^{\frac{3}{2}}$

4. $T^2$ is proportional to $R^{3.75}$

Q.

Name the fundamental force of nature which holds the planets in their orbits around the Sun.

1. Gravitational force of attraction

2. Electrostatic force of attraction

3. Nuclear force of attraction

4. None of these

Q. Let $F,F_N$ and $f$ denote the magnitudes of the contact force, normal force and the frictional force exerted by one surface on the other kept in contact. If none of these is zero,

1. $F>f$
2. $F>F_N$
3. $F_N>f$
4. $F_N-f<F<F_N+f$

Q. Choose the scientist who first performed Galileo's experiment on the moon.

1. Cavendish
2. David Scott
3. Newton
4. none of these

Q. The weight of any person on the moon is about $\frac{1}{6}$ times that on the earth. He can lift a mass of 15 kg on the earth. What will be the maximum mass, which can be lifted by the same force applied by the person on the moon?

Q. The necessary condition for an electrostatic force to act between two bodies is that the __________ .​

Q. During dry weather, while combing hair, sometimes we experience hair flying apart. The force responsible for this is

1. force of gravity.
2. force of friction.
3. electrostatic force.
4. magnetic force.