Gravitation Important Questions.

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1. Q1Easy

   According to Newton’s Universal Law of Gravitation, the gravitational force between two objects is proportional to:

   • A.The sum of their masses
   • B.The product of their masses and inversely proportional to the square of the distance between them
   • C.The difference of their masses
   • D.The direct ratio of their masses
   Answer: The product of their masses and inversely proportional to the square of the distance between them

   Explanation: Newton’s law states that gravitational force (F) is directly proportional to the product of the masses (M × m) of two objects and inversely proportional to the square of the distance (d) between their centers, expressed as F = G × (M × m) / d².

2. Q2Easy

   What is the value of gravitational acceleration (g) on Earth’s surface?

   • A.1.6 m/s²
   • B.9.8 m/s²
   • C.20 m/s²
   • D.4.9 m/s²
   Answer: 9.8 m/s²

   Explanation: The standard value of gravitational acceleration on Earth’s surface is approximately 9.8 meters per second squared.

3. Q3Easy

   What is the gravitational force exerted by Earth on an object of mass 10 kg on its surface?

   • A.10 N
   • B.98 N
   • C.49 N
   • D.196 N
   Answer: 98 N

   Explanation: Using the formula F = m × g, where m = 10 kg and g = 9.8 m/s², the gravitational force is 10 × 9.8 = 98 Newtons.

4. Q4Easy

   Which of the following is an example of an object floating in water?

   • A.A rock
   • B.A metal spoon
   • C.An iceberg
   • D.A steel ship
   Answer: An iceberg

   Explanation: An iceberg floats because its density is less than that of water, allowing it to displace enough water to balance its weight.

5. Q5Easy

   If an object is in free fall, what is the acceleration experienced by the object?

   • A.Zero acceleration
   • B.Constant velocity
   • C.Acceleration due to gravity (g)
   • D.Variable acceleration
   Answer: Acceleration due to gravity (g)

   Explanation: In free fall, the only force acting on the object is gravity, causing it to accelerate at a rate of g, approximately 9.8 m/s².

6. Q6Medium

   What happens to the gravitational force between two objects if the distance between them is reduced to half?

   • A.The force becomes half as strong
   • B.The force remains unchanged
   • C.The force becomes four times stronger
   • D.The force becomes one-fourth as strong
   Answer: The force becomes four times stronger

   Explanation: The gravitational force is inversely proportional to the square of the distance between the objects. If the distance is halved, the force increases by a factor of 2² = 4.

7. Q7Medium

   Why does an object weigh less on the Moon than on Earth?

   • A.The Moon’s atmosphere reduces the object’s weight
   • B.The Moon’s gravitational force is approximately 1/6th of Earth's gravitational force
   • C.The Moon’s distance from the Sun affects the weight
   • D.The Moon’s rotation causes a centrifugal force
   Answer: The Moon’s gravitational force is approximately 1/6th of Earth's gravitational force

   Explanation: The weight of an object on the Moon is less because the Moon's mass is significantly smaller than Earth's, resulting in a weaker gravitational pull. The gravitational acceleration on the Moon is about 1/6th of that on Earth.

8. Q8Medium

   Which of the following is the correct formula for gravitational force between two objects?

   • A.F = G × M × d²
   • B.F = G × (M + m) / d
   • C.F = G × (M × m) / d²
   • D.F = G × (M - m) / d
   Answer: F = G × (M × m) / d²

   Explanation: This formula represents Newton’s Universal Law of Gravitation, where F is the gravitational force, G is the gravitational constant, M and m are the masses of the two objects, and d is the distance between them.

9. Q9Medium

   An object is thrown vertically upwards with an initial velocity of 49 m/s. What is the maximum height it reaches?

   • A.98 meters
   • B.122.5 meters
   • C.49 meters
   • D.245 meters
   Answer: 122.5 meters

   Explanation: Using the equation for uniformly accelerated motion, v² = u² + 2as, where v = 0 at maximum height, u = 49 m/s, and a = -g (acceleration due to gravity = -9.8 m/s²), we get 0 = 49² - 2 × 9.8 × s. Solving for s gives s = 122.5 meters.

10. Q10Medium

    Which of the following is true regarding the buoyant force on an object immersed in a liquid?

    • A.The buoyant force is independent of the liquid’s density
    • B.The buoyant force equals the weight of the displaced liquid
    • C.The buoyant force is always greater than the weight of the object
    • D.The buoyant force depends only on the object's mass
    Answer: The buoyant force equals the weight of the displaced liquid

    Explanation: According to Archimedes' principle, the buoyant force acting on an object submerged in a fluid is equal to the weight of the fluid displaced by the object.

11. Q11Hard

    If the gravitational force between two objects is doubled, what change would occur in their distance if all other factors remain constant?

    • A.The distance would be halved
    • B.The distance would remain unchanged
    • C.The distance would be reduced to √2 times the original distance
    • D.The distance would be doubled
    Answer: The distance would be reduced to √2 times the original distance

    Explanation: Since gravitational force is inversely proportional to the square of the distance, doubling the force would require the distance to be reduced by a factor of √2.

12. Q12Hard

    How does the gravitational force change if the distance between two objects is tripled?

    • A.The gravitational force doubles
    • B.The gravitational force becomes 1/9th of its original value
    • C.The gravitational force remains unchanged
    • D.The gravitational force becomes 1/3rd of its original value
    Answer: The gravitational force becomes 1/9th of its original value

    Explanation: Gravitational force is inversely proportional to the square of the distance. Tripling the distance reduces the force by a factor of 3² = 9.

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