Force Question

1.  Write down the relationship of gravitational force with the distance between two heavenly objects and their masses.
2. What is gravitational constant?
3. Calculate the gravitational force between two masses of 10 kg and 20 kg if they are at 10 meter distance.
4. The earth having the mass 6 × 10²⁴ kg revolves around the sun of mass 2 × 10³⁰ kg in a circular orbit of radius 1.5 × 10¹¹ m. Calculate the force of attraction between them (G = 6.67 × 10^-11 Nm²/kg² ).
5. The mass of the earth is 6 × 10²⁴ kg and its radius is 6400 km. What is the mass of a man weighing 977N in a spring balance?
6. What will happen to the gravitational force of attraction between two bodies when the mass of each body is doubled and the distance between them is tripled?
7. State Newton's law of Gravitation. Calculate the force with which the moon pulls every kilogram of water in our rivers given that the moon is 3 × 10⁵ km away from Nepal and the mass of the moon is 7 × 10²² kg.
8. What happens to the force between two objects, if the distance between the object is doubled?
9. At what condition the value of gravitational force (F) becomes 6.67 × 10^-11 N? Show by calculation.
10. What is gravity?
11. Write the differences between free fall and weightlessness?
12. In which direction the force of gravity act?
13. What's the scientific name of human being?
14. why the gravity of jupiter is only two times greater that that of earth though it has extremly greater mass than earth
15. What will be the effect on the gravitational field intensity of the earth if it is squeezed to the size of the moon? (Given: Radius of the earth = 63.8 × 10⁵ m and radius of the moon = 1.7 × 10⁶ m)
16. A paratrooper lands safely when jumped from a great height, why?
17. Why is the value of "g" greater in Terai region than the Himalayan region?
18. Write three differences between acceleration due to gravity (g) and gravitational constant (G).
19. It is difficult to lift a large stone on the surface of the earth but easy to lift small one, why?
20. The value of "g" is more at poles than at the equator, why?
21. If an iron ball and a feather are dropped simultaneously from the same height in vacuum which one will strike the ground first and why?
22. A feather and a coin fall simultaneously on the surface of the moon, why?
23. The probability of getting hurt is more when a man jumps from a significant height, why?
24. If the mass of the moon is 7.2 × 10²² kg and radius 1.7 × 10⁶ m, what will be acceleration due to gravity of the moon? What will be the weight of a man of 60 kg mass of the moon?
25. The radius of the earth is 6.4 × 10³ km height of the Mount Everest is 8848 m. If the value of "g" at the surface of the earth is 9.8m/s², calculate the value of g at the top of Mount Everest. Also find the weight of the body of mass 25 kg on the top of the Mount Everest.
26. The acceleration due to gravity on the earth is 9.8 m/s². What do you meant by this statement?
27. Prove that the acceleration due to gravity(g) is inversely proportional to the radius of the earth(R).
28. The  mass  of the Jupiter is 1.9  x  10²⁷ kg and its radius is 7.1 x 10 ⁷m. What is the acceleration  due to gravity on the Jupiter?  Also, calculate the weight of a person having mass 60 kg in Jupiter.
29. At what condition a coin and a feather fall together? What is the acceleration of the feather and the coin at that instant? Justify your answer.
30. What is free fall?
31. What is meant by weightlessness?
32. What is the difference between fall of a parachute on the earth and that on the moon?
33. In real life, objects do not fall freely. Give reason.
34.   In the figure below, two identical metal balls A and B having equal masses are being dropped towards the surface of moon and earth. Analyse the given data and answer the following questions: 
    
    
    
1.  If both the metal balls are released simultaneously, which one does strike the ground faster? Show with calculation.
2. A person lifts 30kg on the surface of the earth. How much mass can he lift on the surface of the moon if he applies same magnitude of force?
35.  A meteor is falling towards the Earth. If mass and radius of the earth are 6x10²⁴ kg and 6.4x10³ km respectively. Find the height of meteor from the earth's surface where its acceleration due to gravity becomes 4 m/s². The weight of a body decreases in a coal mine, why?
36. The gravitational force produced between any two objects kept 2.5x10⁴ km apart is 580N. At what distance should they be kept so that the gravitational force becomes half.
37. Clarify the statement, "acceleration due to gravity of the earth is 9.8 m/s²"
38. How much time does a stone take to reach on the surface of the earth drop from the height 20 m and what will be its acceleration due to gravity after 3 seconds. (g = 10 m/s²)
39. Atmosphere is present around the surface of earth but it is not present in the moon, why? The mass of Jupiter is 319 times mass of the earth and its radius is 11 times that of earth. Calculate the acceleration due to gravity on surface of Jupiter also calculate the mass of an object in Jupiter whose mass in Earth is 85kg.