1. Gravity is best defined as:
(A) A force of repulsion between two objects
(B) A pulling force between objects with mass
(C) A contact force caused by friction
(D) A pressure force exerted by fluids
2. The SI unit of gravitational force is:
(A) Pascal
(B) Joule
(C) Newton
(D) Watt
3. The acceleration due to gravity on Earth is approximately:
(A) 8.9 m/s²
(B) 9.8 m/s²
(C) 10.8 m/s²
(D) 12.8 m/s²
4. Weight of an object is calculated as:
(A) Mass ÷ Gravity
(B) Mass × Gravity
(C) Mass + Gravity
(D) Mass − Gravity
5. Which of the following changes with location on Earth?
(A) Mass
(B) Weight
(C) Density
(D) Volume
6. The center of gravity of the human body is generally located near the:
(A) Head
(B) Chest
(C) Navel
(D) Feet
7. Which of the following is NOT influenced by gravity?
(A) Body balance
(B) Blood circulation
(C) Weight of the body
(D) Mass of the body
8. Which scientist first explained gravity mathematically?
(A) Galileo Galilei
(B) Isaac Newton
(C) Albert Einstein
(D) Johannes Kepler
9. Which law explains gravitational attraction?
(A) Newton’s First Law
(B) Law of Universal Gravitation
(C) Law of Inertia
(D) Law of Motion
10. The formula for gravitational force is:
(A) F = ma
(B) F = G m₁m₂/r²
(C) F = mv
(D) F = P/A
11. The value of the universal gravitational constant (G) is:
(A) 9.8 N/kg
(B) 6.67 × 10⁻¹¹ Nm²/kg²
(C) 1.6 × 10⁻¹⁹ Nm²/kg²
(D) 3 × 10⁸ m/s
12. The force of gravity acting on the body is called:
(A) Mass
(B) Weight
(C) Momentum
(D) Pressure
13. On the Moon, the acceleration due to gravity is approximately:
(A) 9.8 m/s²
(B) 6.8 m/s²
(C) 1.6 m/s²
(D) 3.2 m/s²
14. Which of the following decreases with altitude?
(A) Mass
(B) Weight
(C) Density of body
(D) Volume
15. The point where the entire weight of the body is considered to act is called:
(A) Center of mass
(B) Center of gravity
(C) Balance point
(D) Pivot point
16. Which of the following improves stability in standing posture?
(A) Higher center of gravity
(B) Lower center of gravity
(C) Reduced base of support
(D) Narrow stance
17. Astronauts experience weightlessness in space because:
(A) Gravity does not exist
(B) Gravity is negligible everywhere
(C) They are in free fall around Earth
(D) Their mass becomes zero
18. Which body system is most affected by lack of gravity in space?
(A) Digestive system
(B) Skeletal and muscular system
(C) Nervous system
(D) Respiratory system
19. Blood tends to shift towards the head in microgravity due to:
(A) Gravity pulling upward
(B) Lack of gravitational pull
(C) High pressure in legs
(D) Muscle contraction
20. Prolonged absence of gravity can cause:
(A) Stronger muscles
(B) Loss of bone density
(C) Increased joint strength
(D) Higher body mass
21. Which type of exercise is recommended for astronauts to counter gravity loss?
(A) Yoga
(B) Resistance training
(C) Swimming
(D) Jogging
22. Gravity helps maintain:
(A) Posture
(B) Balance
(C) Walking ability
(D) All of the above
23. The human vestibular system relies on gravity for:
(A) Digestion
(B) Balance and orientation
(C) Breathing
(D) Circulation
24. Which of the following is responsible for the sensation of weight?
(A) Mass
(B) Gravity
(C) Pressure
(D) Friction
25. Objects fall at the same rate in absence of:
(A) Gravity
(B) Air resistance
(C) Mass
(D) Weight
26. Free-falling objects appear weightless because:
(A) Gravity disappears
(B) They accelerate at the same rate as gravity
(C) Their mass is zero
(D) Friction is absent
27. Standing on one leg is harder because:
(A) Center of gravity rises
(B) Mass decreases
(C) Base of support is reduced
(D) Weight increases
28. Which sport requires precise control of center of gravity?
(A) Gymnastics
(B) Swimming
(C) Cycling
(D) Weightlifting
29. Which of the following would weigh least?
(A) Person on Earth
(B) Person on the Moon
(C) Person on Jupiter
(D) Person at sea level
30. Gravity on Earth acts towards:
(A) North Pole
(B) South Pole
(C) Center of Earth
(D) Outer atmosphere
31. Why do astronauts float in orbit?
(A) Because no gravity exists in space
(B) Because they are falling with the spacecraft
(C) Because mass becomes zero in space
(D) Because air resistance disappears
32. The force of gravity is directly proportional to:
(A) Distance squared
(B) Mass of objects
(C) Volume of objects
(D) Area of objects
33. The force of gravity is inversely proportional to:
(A) Mass
(B) Square of distance between objects
(C) Volume
(D) Density
34. Gravity plays a role in which of the following daily activities?
(A) Walking
(B) Sitting
(C) Jumping
(D) All of the above
35. Center of gravity in women is slightly:
(A) Higher than men
(B) Lower than men
(C) Same as men
(D) Does not exist
36. An object dropped from height accelerates because of:
(A) Friction
(B) Gravity
(C) Inertia
(D) Elastic force
37. Which organ helps humans detect gravitational pull?
(A) Eyes
(B) Inner ear (vestibular system)
(C) Lungs
(D) Heart
38. The concept of microgravity is experienced:
(A) On Earth’s surface
(B) During free fall in orbit
(C) At sea level
(D) On mountains
39. Which of the following causes tides on Earth?
(A) Earth’s rotation only
(B) Moon’s gravitational pull
(C) Sunlight
(D) Air pressure
40. Astronauts lose height temporarily in space due to:
(A) Expansion of spine in low gravity
(B) Loss of bone mass
(C) Muscle relaxation
(D) Air pressure changes
41. Gravity is weakest at:
(A) Poles
(B) Equator
(C) Mountains
(D) Sea level
42. Which of the following is an adaptation to gravity on Earth?
(A) Strong leg muscles
(B) Upright posture
(C) Skeletal density
(D) All of the above
43. The downward force during parachuting is:
(A) Lift
(B) Gravity
(C) Thrust
(D) Drag
44. Which physical quantity is constant everywhere?
(A) Mass
(B) Weight
(C) Acceleration due to gravity
(D) Pressure
45. The maximum stability of a body is when:
(A) Center of gravity is high
(B) Base of support is narrow
(C) Center of gravity is low and inside base of support
(D) Base of support is absent
46. A gymnast lowers center of gravity by:
(A) Extending arms upward
(B) Crouching
(C) Standing tall
(D) Jumping
47. Gravity provides the necessary:
(A) Inertia for motion
(B) Torque for rotation
(C) Centripetal force for planetary orbits
(D) Elasticity for objects
48. Which of the following is NOT an effect of gravity on humans?
(A) Posture maintenance
(B) Blood flow distribution
(C) Digestion
(D) Increase in body mass
49. Astronauts must exercise in orbit to prevent:
(A) Increase in gravity
(B) Muscle and bone loss
(C) Air pressure drop
(D) Fatigue due to gravity
50. Which of these best explains the role of gravity in biomechanics?
(A) Provides stability, weight, and balance
(B) Changes body mass and density
(C) Increases oxygen consumption
(D) Eliminates internal forces