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प्रश्न
Answer the following:
An astronaut inside a small space ship 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?
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उत्तर १
If the size of the space station is large enough, then the astronaut will detect the change in Earth’s gravity (g).
उत्तर २
Yes. If the size of the spaceship is extremely large, then the gravitational effect of the spaceship may become measurable. The variation in g can also be detected.
संबंधित प्रश्न
What happens to the force between two objects, if the distance between the objects is doubled and tripled?
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.
A body is suspended from a spring balance kept in a satellite. The reading of the balance is W1 when the satellite goes in an orbit of radius R and is W2 when it goes in an orbit of radius 2 −R.
Consider a planet moving in an elliptical orbit round the sun. The work done on the planet by the gravitational force of the sun
(a) is zero in any small part of the orbit
(b) is zero in some parts of the orbit
(c) is zero in one complete revolution
(d) is zero in no part of the motion.
Two spherical balls of mass 10 kg each are placed 10 cm apart. Find the gravitational force of attraction between them.
A ball is thrown up with a speed of 4.9 ms-1.
Calculate the time it takes to reach this height.
What is meant by the equation :
`g= Gxxm/r^2`
where the symbols have their usual meanings.
Two equal and opposite forces acting at the same point on a stationary body. Will the body move? Give reason to explain your answer.
Gravity is another kind of ________. It exerts all through the ________. The Sun's gravity keeps the ___________ in their orbits. Gravity can only be felt with very large ________.
Explain why:
The atmosphere does not escape.
State Newton's law of gravitation. What is the difference between:
g and G?
Answer the following question.
State Newton’s law of gravitation and express it in vector form.
The gravitational force between two bodies is directly proportional to the product of the masses of those bodies and is _______ of the distance between them.
The value of universal gravitational constant (G) in the SI unit is ______.
State the universal law of gravitation and derive its mathematical expression.
Different points in earth are at slightly different distances from the sun and hence experience different forces due to gravitation. For a rigid body, we know that if various forces act at various points in it, the resultant motion is as if a net force acts on the c.m. (centre of mass) causing translation and a net torque at the c.m. causing rotation around an axis through the c.m. For the earth-sun system (approximating the earth as a uniform density sphere).
If the law of gravitation, instead of being inverse-square law, becomes an inverse-cube law- ______.
- planets will not have elliptic orbits.
- circular orbits of planets is not possible.
- projectile motion of a stone thrown by hand on the surface of the earth will be approximately parabolic.
- there will be no gravitational force inside a spherical shell of uniform density.
If three equal masses m are placed at the three vertices of an equilateral triangle of side 1/m then what force acts on a particle of mass 2m placed at the centroid?
