Q.1.
A body of mass 1 kg is placed at a distance of 2m from another body
of mass 10kg. At what distance from the body of 1 kg, another body of
mass 5 kg be placed so that the net force of gravitation acting on the body
of mass 1 kg is zero?
Q.2. A geostationary satellite is orbiting the earth at a height 5 R above the
surface of earth, where R is the radius of earth. Find the time period of
another satellite at a height of 2 R from the surface of earth.
Q.3. The distance of planet Jupiter from the sun 5.2 times that of Earth.
Find the period of revolution of Jupiter around sun.
Q.4. If the distance of Earth from the Sun were half the present value, how
many days will make one year?
Q.5. The gravitational force between two objects is F. How will this force
change when (i) distance between them is reduced to half (ii) the mass of
each object is quadrupled?
Q.6. A sphere of mass 25kg attracts another sphere of mass 24kg with a
force of 0.1milligram weight. If distance between the centres of two
spheres is 20cm, what is the value of G?
Q.7. A sphere of mass 40kg is attracted by a second sphere of mass 15kg
when their centres are 20 cm apart, with a force of 0.1 milligram weight.
Calculate the value of gravitational constant.
Q.8. If distance between two masses is quadrupled, what will be the new
force of attraction between them? Given the initial gravitational pull is
9.8N.
Q.9. An electron of mass 9.1 x 10–31kg is at a distance of 10 A0 from a
proton of mass 1.67×10-27 kg. Calculate the gravitational force of attraction
between them. Given 1 A0=10-10m
Q.10. Two bodies A and B having masses 20kg and 40kg are separated by
10m. At what distance from body A should another body C of mass 15kg
be placed so that net gravitational force on C is zero?
Q.11. Two satellites of a planet have periods 32 days and 256 days. If the
radius of orbit of former is R, find the orbital radius of the latter.
Q.12. The mass of Earth is 6 x 1024 kg and that of moon is 7.4 x 1022 kg. If
the distance between the Earth and the Moon is 3.84 x 10 5 km, calculate
the force exerted by Earth on the Moon. Given G = 6.7 x 10–11 Nm2/kg2.
Q.13. If the distance between two masses is increased by a factor of 4, by
what factor would the mass of one of them have to be altered to maintain
the same gravitational force?
Q.14. The mass of Sun is 2 x 1030 kg and mass of Earth is 6 x 1024 kg. If the
distance between the centres of Sun and Earth is 1.5 x 10 8 km, calculate
the force of gravitation between them.
Q.15. Two electrons each of mass 9.1 x 10 –31 kg are at a distance of 10 A0 .
Calculate the gravitational force of attraction between them. Given 1
A0=10-10m
Q.16. The gravitational force between force two objects is 100 N. How
should the distance between these objects be changed so that force
between them becomes 50 N?
Q.17. Calculate the force of gravitation between two objects of masses
80kg and 1200 kg kept at a distance of 10 m from each other. Given G =
6.67 x 10–11 Nm2/kg2.
Q.18. Calculate the force of attraction between the Earth and the Sun,
given that the mass of Earth is 6 x 1024 kg and that of sun is 2 x 1030 kg.
The average distance between the two is 1.5 x 1011m.
Q.19. Calculate the gravitational force on a body of mass 1kg lying on the
surface of earth. Given mass of earth is 6 x 1024 kg and radius of earth is
6400km.
Q.20. Two bodies A and B having masses 2kg and 4kg respectively are
separated by 2m. Where should a body of mass 1kg be placed so that the
gravitational force on this body due to bodies A and B is zero?
Q.21. A stone drops from the edge of a roof. It passes a window 2m high
in 0.1s. How far is the roof above the top of the window?
Q.22. A stone is dropped from the edge of a roof. (a) How long does it
take to fall 4.9m ? (b) How fast does it move at the end of that fall? (c)
How fast does it move at the end of 7.9m? (d) What is its acceleration after
1s and after 2s?
Q.23. An object is thrown vertically upwards and rises to a height of 10m.
Calculate (i) the velocity with which the object was thrown upwards and
(ii) the time taken by the object to reach the highest point.
Q.24. A force of 2 kg wt. acts on a body of mass 4.9kg. Calculate its
acceleration.
Q.25. A force of 20N acts upon a body weight is 9.8N. What is the mass of
the body and how much is its acceleration?
Q.26. A body has a weight of 10 kg on the surface of earth. What will be
its mass and weight when taken to the centre of earth?
Q.27. How much would a 70 kg man weigh on moon? What will be his
mass on earth and moon? Given g on moon = 1.7 m/s2.
Q.28. The Earth’s gravitational force causes an acceleration of 5 m/s 2 in a
1 kg mass somewhere in space. How much will the acceleration of a 3 kg
mass be at the same place?
Q.29. A particle is thrown up vertically with a velocity of 50 m/s. What
will be its velocity at the highest point of the journey? How high would the
particle rise? What time would it take to reach the highest point? Take g =
10 m/s2.
Q.30. Calculate the force of gravity acting on your friend of mass 60 kg.
Given mass of earth= 6×1024 kg and radius of Earth = 6.4 x 106m.
Q.31. Mass of an object is 10kg. What is its weight on Earth?
Q.32. What is the mass of an object whose weight is 49N?
Q.33. An object weighs 10N when measured on the surface of the earth.
What would be its weight when measured on the surface of the Moon?
Q.34. If a planet existed whose mass was twice that of Earth and whose
radius 3 times greater, how much will a 1kg mass weigh on the planet?
Q.35. A boy on cliff 49m high drops a stone. One second later, he throws a
second stone after the first. They both hit the ground at the same time.
With what speed did he throw the second stone?
