Physics Work sheet 2017E.
AT ADAMA MODEL SENIOR SECONDARY SCHOOL PHYSICS WORK SHEET
ON NEWTON’S LAW OF UNIVERSALGRAVITATION AND KEPLER’S LAW (G-12)
Direction: Choose the best answer among given alternatives.
1. Two masses of and are balanced on a horizontal stick of negligible mass pivoted at the center of mass of
system. If the distance from to the center of mass is 3m and the distance from to the center of mass is 1m,
the ratio of to is
A. 4/3 B. 3/4 C. 3 D. 1/3
2. According to Newton’s law of universal gravitation
A. For two interacting objects gravitational force exerted on a light object is less than the force on the heavy one
B. Speed of satellite moving around the earth in a circular orbit depends on the mass of satellite
C. Gravitational attraction between two objects is directly proportional to the square of distance between them
D. Period of a satellite orbiting earth in a circular orbit increases as radius of its orbit increases
3. A satellite revolves around the earth in a circular orbit of radius . The period of the satellite is
A. B. C. D.
4. As a satellite moves in elliptical orbit around the earth, the gravitational attraction of the earth for the satellite:
A. is greater than the satellites gravitational attraction for the earth
B. is less than the satellites gravitational attraction for the earth
C. varies inversely as the square to the distance between earth and satellite
D. remains constant
5. The orbital speed of satellites at a height of 780km from the surface of earth is 7465m/s. What is the period of
satellite?
A. B. C. D.
6. What is the acceleration due to gravity at an altitude twice the radius of the earth?( is acceleration due to
gravity on the surface of the earth)
A. B. C. D.
7. Which one of the following statements is correct about Newton’s law of universal gravitation?
A. gravitational force between two objects is repulsive
B. gravitational force between two objects is either repulsive or attractive
C. gravitational force between two objects is independent of objects masses
D. gravitational force between two objects is inversely proportional to the square if their separation
By: Denebo Dekebo Worwachiso Page 1
Physics Work sheet 2017E.C
8. The distance of two planets from the sun are m and m, respectively. The ratio of time periods
to is:
A. B. C. √ D. √
√
9. Suppose two satellites of different masses are launched from the surface of the earth and revolve around the earth
at different orbital radiuses. Which one of the following statements is correct about the motions of the two
satellites?
A. Satellite with heavier mass takes longer time to make one revolution around its orbit
B. Satellite with heavier mass is launched with larger speed
C. Satellite with smaller orbital radius revolves with larger orbital velocity
D. Satellite with larger orbital radius is launched with larger speed
10. What is the mass of planet that has a satellite whose time period is T and orbital radius is r?
A. B. C. D.
11. A satellite moves in a circular orbit at a constant speed around earth. Which of the following statement is
true?
A. No force acts on the satellite
B. Satellite moves at constant speed and hence doesn’t accelerate
C. Satellite has an acceleration directed away from earth
D. Satellite has an acceleration directed toward earth
12. Two satellites of masses and ( ) are revolving around the earth in a circular orbit of radii
and ( ), respectively. Which of the following is true regarding to their speeds and ?
A. B. C. D.
13. The value of at certain height above the free surface of the earth is where is the value of at the
surface of earth. The height is
A. B. C. D.
14. What is the gravitational acceleration close to the surface of a planet with twice the mass and twice the radius
of earth? ( is gravitational acceleration on earth’s surface)
A. B. C. D.
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Physics Work sheet 2017E.C
15. The planet is revolving around the sun as shown below in elliptical path. Which option is correct?
A. Time taken in travelling DAB is less than that for BCD
B. Time taken in travelling DAB is greater than that for BCD
C. Time taken in travelling CDA is less than that for ABC
D. Time taken in travelling CDA is greater than that for ABC
16. A body has weight W at the surface of the earth. Its weight at a height equal to half the radius of the earth will
be
A. B. C. D.
17. Kepler’s second law is based on
A. Newton’s first law B. Newton’s second law
C. Special theory of relativity D. Conservation of angular momentum
18. Earth needs one year to complete one revolution round the sun. If the distance between sun and earth is
doubled then the period of revolution of earth will become
A. √ B. C. D.
19. The central point to describe that Newton’s law of universal gravitation is a basis for understanding Kepler’s
laws is that is gives a
A. constant tangential velocity of rotating planets
B. constant angular acceleration for a revolving planet
C. centripetal force for planets revolving around the sun
D. tangential force while planets revolve about the sun
20. A satellite moves in a circular orbit around earth at a speed of 5000m/s. Determine
a. Satellite’s altitude above the surface of earth
b. Period of the satellite’s orbit
By: Denebo Dekebo Worwachiso Page 3
