Advertisements
Advertisements
Question
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?
Advertisements
Solution 1
If the size of the space station is large enough, then the astronaut will detect the change in Earth’s gravity (g).
Solution 2
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.
RELATED QUESTIONS
The earth and the moon are attracted to each other by gravitational force. Does the earth attract the moon with a force that is greater or smaller or the same as the force with which the moon attracts the earth? Why?
Choose the correct alternative:
Acceleration due to gravity is independent of mass of the earth/mass of the body.
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 rocket is fired from the earth towards the sun. At what distance from the earth’s centre is the gravitational force on the rocket zero? Mass of the sun = 2 ×1030 kg, mass of the earth = 6 × 1024 kg. Neglect the effect of other planets etc. (orbital radius = 1.5 × 1011 m).
How will you ‘weigh the sun’, that is estimate its mass? The mean orbital radius of the earth around the sun is 1.5 × 108 km.
State two applications of universal law of gravitation.
Two small bodies of masses 10 kg and 20 kg are kept a distance 1.0 m apart and released. Assuming that only mutual gravitational forces are acting, find the speeds of the particles when the separation decreases to 0.5 m.
Two concentric spherical shells have masses M1, M2 and radii R1, R2 (R1 < R2). What is the force exerted by this system on a particle of mass m1 if it is placed at a distance (R1+ R2)/2 from the centre?
A particle of mass 100 g is kept on the surface of a uniform sphere of mass 10 kg and radius 10 cm. Find the work to be done against the gravitational force between them to take the particle away from the sphere.
Is the law of gravitation applicable in case of the sun and the moon?
A ball is thrown up with a speed of 4.9 ms-1.
Calculate the maximum height it would gain before it begins to fall.
Where will you weigh more: at the moon's surface or at the earth's surface?
What does a force do in the following case?
You twist a piece of rubber.
Name and state the action and reaction in the following case:
A book lying on a table.
Name and state the action and reaction in the following case:
A person walking on the ground.
Does the force of the earth's gravitation affect the motion of the moon? Explain your answer with reasons.
The value of universal gravitational constant (G) in the SI unit is ______.
Newton's universal law of gravitation applies to ______.
Observe the figure and answer the questions:

- State Newton's universal law of gravitation.
- If the distance between the two bodies is tripled, how will the gravitational force between them change?
- What will happen to gravitational force, if mass of one of the object is doubled?
