Physics · Science General

Newtonian Mechanics and Forces

1,559 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

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.

Multiple choice

Newton's second law of motion states that, ''The rate of change of momentum is _____________''.

  1. directly proportional to F in the direction of force

  2. inversely proportional to F in the direction of force

  3. inversely proportional to F in the opposite direction of force

  4. directly proportional to F in the opposite direction of force

  5. directly proportional to F and independent of direction of force
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

 Yes, the rate of change of momentum increases and the increase is in the direction of motion because the force is being applied in the direction of motion.

Multiple choice

Ramesh wanted to move his hand freely in gas, liquid and solid. But could not move in solid, which of the following is the best reason?

  1. Solid is made up of one hard particle

  2. Solid particles keep randomly moving

  3. Solid particles have no space in between

  4. As Sri was applying less force

  5. The surface of solid particles is slippery
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Yes, the force of attraction between particles of solid isthe greatest. To move our hand in liquid, such as water, we have to apply some force, but in a solid such as wood, we cannot move our hand.

Multiple choice

The hole in a parachute is there

  1. to avoid oscillation

  2. to decrease strength

  3. to lighten the weight of a person

  4. for conduction of heat
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The hole in the center of a parachute allows air to escape through it, which prevents the parachute from oscillating or swinging back and forth during descent. Without this hole, air would get trapped and cause dangerous pendulum-like motion. Option B is incorrect because the hole does not decrease the parachute's structural strength. Option C is wrong because the hole's size is negligible for weight reduction. Option D is irrelevant - heat conduction has nothing to do with parachute function.

Multiple choice

The centripetal force is always acting

  1. towards the centre

  2. outwards

  3. tangentially

  4. both 2 and 3

  5. both 1 and 2
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

In uniform circular motion, acceleration is caused due to change in direction and is directed radially towards centre.