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

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.

Multiple choice

The force of attraction between any two objects is called

  1. gravitational force

  2. frictional force

  3. electrostatic force

  4. magnetic force

  5. electromotive force
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

According to Newton all objects in the universe attract each other. This force of attraction between the objects is called gravitational force or gravity. So it is correct.

Multiple choice

When does force of friction come into play?

  1. When a body stops its movement

  2. When a body does not start its movement

  3. After sliding through some distance

  4. When a body slides or tends to do it on the surface of other body
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

 When a body slides on the surface of other body.

Multiple choice

What happens when one object moves over the surface of another object?

  1. Surface of only upper object exerts force of friction on lower object.

  2. Surface of lower object exerts force of friction on upper object.

  3. Surface of both the objects exerts force on each other.

  4. Surface of both the objects exerts force in a direction opposite to each other.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

According to Newton's third law, when two surfaces slide against each other, BOTH surfaces experience friction forces. These forces are equal in magnitude but opposite in direction - each surface exerts friction on the other. Option A incorrectly suggests only the upper object exerts friction, option B incorrectly suggests only the lower object does, and option C is incomplete. Option D correctly captures that both surfaces exert friction forces in opposite directions.

Multiple choice

How is frictional force helpful in walking?

  1. Frictional force is exerted on the ground by foot.

  2. It produces heat which helps in walking.

  3. If there was no friction, your foot would simply slide back as you tried to take steps, and you would go nowhere.

  4. It prevents the foot from slipping forward.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

 If there was no friction, your foot would simply slide back as you tried to take steps, and you would go nowhere.

Multiple choice

Which of the following statements is/are true?

  1. Tyres have geometrical pattern to reduce the friction.
  2. The straps of the shoulder bags are made broad to decrease the pressure by increasing the area of contact
  3. Aeroplanes and boats have streamlined shapes to reduce the resistance offered by air and water, respectively.

  1. Only (1)

  2. Only (2)

  3. Only (1) & (3)

  4. Only (2) & (3)
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Statement (1) is wrong. Tyres and soles of shoes have geometrical patterns to increase the friction. Statement (2) is correct. The straps of the shoulder bags are made broad to decrease the pressure by increasing the area of contact. Statement (3) is correct. Aeroplanes and boats have streamlined shapes to reduce the resistance offered by air and water, respectively.