Question

A)You can sheild a charge from electrical forces by putting it inside a hollow conductor. Can you sheild a body from the gravitational influence of nearby matter by putting it inside a hollow sphere or by some other means?

B)An astronaut inside a small spaceship orbiting around the earth cannot detect gravity. If the space station orbiting around the earth has a large size, can he hope to detect gravity?

C)If you compare the gravitational force on the earth due to the sun to that due to the moon, you would find that the Sun's pull is greater than the moon's pull, (you can check this yourself using the data avaliable in the succeeding exercise). However, the tidal effect of the moon's pull is greater than the tidal effect of sun. Why?

Answer 1

A)No, because the gravitational force of attarction on a point mass situated inside a spherical inside a spherical shell is zero.

B)Yes, an astronanut inside the spaceship can detect the variation in gravity, if the size of the spaceship is large enough.

C)Tidal effect depends inversely on the cube of the distance, unlike force, which depends inversely on the square of the distance. Since the distance of moon from ocean water is very small as compared to the distance of sun from the ocean water on earth. Therefore, the tidal effect of moon's pull is greater than the tidal effect of the sun.