Physics · Science General

Newtonian Mechanics and Forces

1,605 Questions

Newtonian mechanics studies the motion of objects and the physical laws governing them. This hub covers friction, gravitational force, inertia, and vector quantities. Mastering these fundamental physics concepts is essential for various government competitive exams.

Laws of motionFriction and inertiaVector and scalar quantitiesGravitational accelerationArchimedes principle

Newtonian Mechanics and Forces Questions

Multiple choice

When a loaded and an empty truck of identical specifications are moving with same velocity, more force is required to stop the loaded truck. Which of the following laws is proved by this action?

  1. Newtons' first law of motion

  2. Newtons' second law of motion

  3. Newtons' third law of motion

  4. Gravitational law
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Newton's second law (F = ma) explains this - the loaded truck has more mass (m), so at the same velocity, it has more momentum. Stopping it requires more force to produce the deceleration. Newton's first law describes inertia, third law describes action-reaction pairs, and gravitational law governs attraction between masses.

Multiple choice

If a body is moving uniformly in a straight line, the force on the body is

  1. maximum

  2. minimum

  3. zero

  4. average
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

When a body moves uniformly in a straight line, its velocity is constant (both speed and direction unchanged). By Newton's first law, this means zero net force acts on it. Zero force is neither maximum, minimum, nor average - it's simply zero. Any acceleration would require a net force, causing non-uniform motion.

Multiple choice

Which of the following forces is the weakest?

  1. Nuclear force

  2. Electromagnet force

  3. Gravitational force

  4. Electrostatic
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Among the four fundamental forces of nature, gravitational force is the weakest by far - approximately 10^36 times weaker than the strong nuclear force and 10^25 times weaker than electromagnetic force. Nuclear force is strongest, followed by electromagnetic, then weak nuclear, with gravity being weakest.

Multiple choice

A pile of carom coins is hit with a striker, the lowest coin moves away but rest of the pile stays as it is in rest, moving down. Which of the following explains it best?

  1. The pile of coin weighs more than the single coin pushed away.

  2. The pile of coin has more volume.

  3. The pile of the coin possess inertia of rest.

  4. The space created by the lowest coin had to be occupied.

  5. More force was required to make the pile of coin fall.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Yes, it is correct. It is inertia because of which an object in rest has tendency to remain in rest. The pile of coin already in rest, continues to remain in rest.

Multiple choice

Which of the following statements is false regarding gravitation?

  1. Physical bodies are attracted towards each other.

  2. The pull of Earth can be seen.

  3. An object falls towards the ground when dropped from a height.

  4. It gives weight to the object.

  5. None of these
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Yes, it is the correct answer, as this statement is incorrect. Earth attracts everything towards it by an unseen force of attraction.

Multiple choice

Free fall is a kind of motion that everybody can observe in daily life. How is the speed affected? After starting (S1), midway (S2), just before crash (S3), on touching the ground (S4)

  1. S1 > S2 > S3 > S4

  2. 0 < S2 < S3 > 0

  3. S1 < S2 < S3 > 0

  4. S1 < S2 < S3 < S4

  5. 0 < S2 < S3 > S4
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Yes, at the beginning it has less speed and until the end it gains speed and before the crash it reaches its maximum speed. Then, after the crash it becomes zero.

Multiple choice

In a solid, the particles are ……………. together. The forces between particles are ………………. so that the particles cannot move freely but can only vibrate.

  1. closely packed, weak

  2. loosely packed, strong

  3. closely packed, strong

  4. loosely packed, weak

  5. unpacked, strong
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

In a solid, the particles (ions, atoms or molecules) are closely packed together. The forces between particles are strong so that the particles cannot move freely but can only vibrate. As a result, a solid has a stable, definite shape, and a definite volume. Solids can only change their shape by force as when broken or cut.

Multiple choice

When milk is churned, cream is separated due to

  1. gravitational force

  2. centrifugal force

  3. frictional force

  4. none of these
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

When milk is churned, centrifugal force causes the lighter cream (fat) to separate from the denser skim milk. The spinning motion pushes the heavier milk outward while the lighter cream collects, allowing it to be removed - this is the same principle used in mechanical cream separators.