Friday, 14 October 2016


Q1. The mass of moon is nearly 10% of the mass of the earth. What will be the gravitational force of the earth on the moon, in comparison to thegravitational force of the moon on the earth?
Q2. Why does one feel giddy while moving on a merry go round?
Q3. Name two factors which determine whether a planet would have atmosphere or not.
Q4. The force of gravity due to earth on a body is proportional to its mass, then why does a heavy body not fall faster than a lighter body?
Q5. The force of attraction due to a hollow spherical shell of uniform density on a point mass situated inside is zero, so can a body be shielded from gravitational influence?
Q6. The gravitational force between two bodies in 1 N if the distance between
them is doubled, what will be the force between them?
Q7. A body of mass 5 kg is taken to the centre of the earth. What will be its (i) mass (ii) weight there.
Q8. Why is gravitational potential energy negative?
Q9. A satellite revolves close to the surface of a planet. How is its orbital velocity related with escape velocity of that planet.
Q10. Does the escape velocity of a body from the earth depend on (i) mass of the body (ii) direction of projection
Q11. A satellite does not require any fuel to orbit the earth. Why?
Q12. A satellite of small mass burns during its desent and not during ascent.Why?
Q13. Is it possible to place an artificial satellite in an orbit so that it is always
visible over New Delhi?
Q14. If the density of a planet is doubled without any change in its radius,how does ‘g’ change on the planet.
Q15. Why is the weight of a body at the poles more than the weight at the
equator? Explain.
Q16. Why an astronaut in an orbiting space craft is not in zero gravity although
he is in weight lessness?
Q17. Write one important use of (i) geostationary satellite (ii) polar satellite.
Q18. A binary star system consists of two stars A and B which have time periods TA and TB, radius RA and RB and masses mA and mB which of the three quantities are same for the stars. Justify.
Q19. The time period of the satellite of the earth is 5 hr. If the separation
between earth and satellite is increased to 4 times the previous value,
then what will be the new time period of satellite.
Q21. Why does the earth impart the same acceleration to every bodies?
Q22. If suddenly the gravitational force of attraction between earth and satellite

become zero, what would happen to the satellite?