EDU Station
GRAVITATION
CALL : 3200 3200
CCE. QUESTIONS
1. Calculate the fore of gravitation between two objects of masses 10 kg and 20 kg at a distance of 10 m from
each other [G = 6.67 x 10-11 Nm2kg-2]
2. The mass of the earth is 6 x 1024 kg and that of the moon is 7.4 x 1022 kg. If the distance between the earth
and the moon be 3.84 x 105 km, calculate the force exerted by the earth on the moon. (G = 6.67 x 10-11 Nm2
kg-2)
3. The mass of earth is 6 x 1024 kg and that of a natural satellite is 6.5 x 1020 kg. If the distance between them is
3.35 x 106 km, calculate the force exerted by earth on it. (G = 6.7 x 10-11 Nm2kg-2)
4. A stone is released from the top of a tower of height 19.6 m. Calculate its velocity just before touching the
ground
5. The mass of the earth is 6 x 1024 kg. The radius of the earth is 6.4 x 106 m, and the gravitational constant is
6.7 x 10-11 Nm2/kg2. Calculate the value of g
6. A ball is thrown vertically upwards with a velocity of 49 ms-1. Calculate
(i) The maximum height to which it rises
(ii) The total time it takes to return to the surface of the earth
7. A boy drops a ball from a cliff 122.5 m high. Find
(i) How long does it take the ball to fall to the ground?
(ii) How far does it fall in the 1st three seconds?
(iii) How fast is it going at the end of three seconds?
8. A ball thrown vertically up returns to the thrower after 6 s. Find
(i) the velocity with which it was thrown up
(ii) the maximum height it reaches
(iii) its position after 4s.
9. A ball thrown vertically upwards rises to a height of 20m. Calculate
(i) The velocity with which ball is thrown upwards.
(ii) The time taken by ball to reach the highest point ( g = 10 m/s2 )
10. A stone is allowed to fall down from the top of a tower 100m high and at the same time another stone is
projected vertically upwards from the ground with a velocity of 25m/s. Calculate when and where the two
stones will meet? ( g = 10 m/s2 )
11. A car falls off a ledge and drops to the ground in 0.5 s. Let g = 10 m/s2
(i) What is its sped on striking the ground?
(ii) What is its average speed during the 0.5 s?
(iii) How high is the ledge from the ground?
12. A body of weight 600 N rests on the floor of a lift. If the lift begins to fall freely under the gravity, what is
the force with which the body presses on the floor?
13. Two stones A and B are dropped from a multistoreied building. A is dropped from 100 m and after some
time B is dropped from 50 m height. Both of them reach the earth at the same time. Will they have equal
velocity while reaching the ground? Calculate and find out the answer (take g = 10 m/s2)
14. A firecracker is fired and it t\rises to a height of 1000 m. Find the
(i) Velocity by which it was released
(ii) Time taken by it to reach the highest point [take g = 9.8 m/s2]
15. Gravitational force on an imaginary planet is six times stronger than the gravitational force of the earth.
Determine the value of acceleration due to gravity and weight of an object of mass 50 kg on that planet
16. A man weight 600 N on the surface of earth. What would be his mass and weight on surface of moon? (g =
10 m/s2)
17. A body weighs 30 kg on the surface of earth. How much would it weight on the surface of a planet whose
mass is th the mass of earth and radius is half that of earth
18. Find the weight of an object at a height 6400 km above the earth’s surface. The weight of the object at the
surface of the earth is 20 N and the radius of the earth is 6400 km
19. The ratio of the gravitational force on Neptune to the gravitational force on earth is 9 : 8. Ramesh weights
792 N on Earth. Calculate his weight on Neptune
20. A particle weighs 120 N on the surface of the earth. At what height above the earth’s surface will its weight
be 30 N? Radius of earth = 6,400 km