Advertisements
Advertisements
Question
A thin spherical shell having uniform density is cut in two parts by a plane and kept separated as shown in the following figure. The point A is the centre of the plane section of the first part and B is the centre of the plane section of the second part. Show that the gravitational field at A due to the first part is equal in magnitude to the gravitational field at B due to the second part.

Advertisements
Solution
We know that in a thin spherical shell of uniform density, the gravitational field at its internal point is zero. So, at points A and B, the gravitational fields are equal and opposite and, thus, cancel each other. So the net field is zero.
Hence, EA = EB

APPEARS IN
RELATED QUESTIONS
Write the formula to find the magnitude of the gravitational force between the earth and an object on the surface of the earth.
What is the magnitude of the gravitational force between the earth and a 1 kg object on its surface? (Mass of the earth is 6 × 1024 kg and radius of the earth is 6.4 × 106 m).
Answer the following:
You can shield a charge from electrical forces by putting it inside a hollow conductor. Can you shield a body from the gravitational influence of nearby matter by putting it inside a hollow sphere or by some other means?
The gravitational intensity at the centre of a hemispherical shell of uniform mass density has the direction indicated by the arrow (see Fig 8.12) (i) a, (ii) b, (iii) c, (iv) 0.

Write the three laws given by Kepler. How did they help Newton to arrive at the inverse square law of gravity?
A tunnel is dug along a diameter of the earth. Find the force on a particle of mass m placed in the tunnel at a distance x from the centre.
A solid sphere of mass m and radius r is placed inside a hollow thin spherical shell of mass M and radius R as shown in the following figure . A particle of mass m' is placed on the line joining the two centres at a distance x from the point of contact of the sphere and the shell. Find the magnitude of the resultant gravitational force on this particle due to the sphere and the shell if (a) r < x < 2r, (b) 2r < x < 2R and (c) x > 2R.

Multiple Choice Question. Select the correct option.
The mass of earth is 6 × 1024 kg and radius of earth is 6.4 × 106 m. The magnitude of force between the mass of 1 kg and the earth is:
How will the force of gravitation between two objects change if the distance between them is:
Almost zero
Why don't you feel the force of attraction between your friend sitting close to you and yourself?
A force can produce ________, In an object at rest. It can __________ an object and change its __________ of motion.
Name and state the action and reaction in the following case:
A person walking on the ground.
State the law of gravitation. Why is it called universal?
State Newton's law of gravitation. What is the difference between:
Gravity and gravitation
The ______ force is much weaker than other forces in nature.
The gravitational force between a hollow spherical shell (of radius R and uniform density) and a point mass is F. Show the nature of F vs r graph where r is the distance of the point from the centre of the hollow spherical shell of uniform density.
Shown are several curves (Figure). Explain with reason, which ones amongst them can be possible trajectories traced by a projectile (neglect air friction).
Ocean tides on Earth are mainly caused by ______.
The acceleration of the Moon towards the Earth is approximately ______.
The gravitational force between two objects acts in which direction?
