Physics ยท 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

Which of the following statements is incorrect?

  1. Friction is a necessary evil.

  2. Friction cannot be reduced.

  3. Static friction comes into play when we try to move an object at rest.

  4. Rolling friction is always less than sliding friction.

  5. Friction is caused due to interlocking of irregularities on the two surfaces in contact with each other.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Friction can be reduced by using lubricants, soap solution or by polishing, etc.

Multiple choice

Which of the following forces can act from a distance?

  1. Chemical and Electrical forces

  2. Gravitational and Magnetic forces

  3. Mechanical and Elastic forces

  4. Friction and Hydrostatic forces
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Solution: Forces can be categorized as contact and non-contact forces. The examples of non- contact forces are Gravitational, magnetic, electrostatic, etc. The examples of contact forces are friction, chemical, electrical, etc.

Multiple choice

The centre of mass of a body depends upon which of the following factors?

  1. Size of the body
  2. Shape of the body
  3. Position of the body

  1. Only 1

  2. Only 1 and 3

  3. Only 2

  4. Only 1, 2 and 3
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The centre of mass of a rigid body is a point whose position is fixed with respect to the body as a whole. The point may or may not lie in the body. The position of the centre of mass of a rigid body depends on the following:

(1) Shape of the body (2) Distribution of mass in the body

Multiple choice

Which of the following statements about motion is incorrect?

  1. A body moving with uniform speed can have non uniform velocity.

  2. A body moving with uniform acceleration can be at rest at an instant.

  3. An accelerating body may move with constant speed.

  4. A body moving with constant velocity can have varying speed.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Solution: A body can have a constant speed but a changing velocity because the direction can change while the speed is constant.

Multiple choice

Consider the following statements:

  1. When we jump out from a boat standing in water, it moves forwards.
  2. Weight of a body is lesser in plains and greater on hilltops.

Which of the given statements is/are incorrect?

  1. Only 1

  2. Only 2

  3. Both 1 and 2

  4. Neither 1 nor 2
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Statement 1 is incorrect. The action being you jumping imparts an equal force on the boat pushing it backwards with only drag to resist its motion. Statement 2 is also incorrect. Weight of a body is greater in plains and lesser on hilltops.

Multiple choice

Consider the following statements:

  1. When a bomb is thrown from an aeroplane, it will follow a straight path.
  2. Work done by a body in circular motion is zero.

Which of the given statements is/are correct?

  1. Only 1

  2. Only 2

  3. Both 1 and 2

  4. Neither 1 nor 2
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Statement 1 is incorrect. When a bomb is thrown from an aeroplane, it will follow a hyperbolic path. Statement 2 is correct. Work done by a body in a circular motion is zero, because the force applied and displacement makes the angle of 900.

Multiple choice

Which of the following is/are example of centripetal force?

  1. Roller coaster
  2. Turning of wheels in circular track
  3. Whirling of a stone tied to a string
  4. Rotation of tubes containing a mixture at high speed for precipitation

  1. Both 1 and 2

  2. Only 4

  3. 1, 2 and 3

  4. None of these
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Centripetal force is a force that makes a body to follow a curved path. E.g.

  1. Roller coaster
  2. Turning of wheels in circular track
  3. Whirling of a stone tied to a string Centrifugal force is the apparent outward force that draws a rotating body away from the center of rotation. Rotation of tubes containing a mixture at high speed for precipitation is called centrifugation.
Multiple choice

A kite when flying in the air has _____________.

  1. kinetic energy

  2. potential energy

  3. both potential energy and kinetic energy

  4. neither kinetic energy nor potential energy

  5. kinetic and muscular energy
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

A kite when flying in the air possesses only kinetic energy.

Multiple choice

In a freely falling body, the interchange of energy takes place __________________.

  1. gradually from potential to kinetic energy

  2. gradually from kinetic to potential energy

  3. alternately between potential and kinetic

  4. gradually from chemical to kinetic energy

  5. gradually from potential to chemical energy
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

In a freely falling body, the interchange of energy takes place gradually from potential to kinetic energy.

Multiple choice

Pressure is defined as

  1. force acting per unit area

  2. area acting per unit force

  3. product of force and area

  4. product of mass and area

  5. product of mass and gravitational force
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The value of the force acting over per unit area is called pressure.

Multiple choice

Which of the following is not an example of contact force?

  1. Lifting a bucket full of water.

  2. A car moving with the help of a machine.

  3. A fan moving with the help of a motor fitted in it.

  4. A bus and a car colliding with each other.

  5. Falling of a ball or stone thrown towards the sky.
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

It is an example of gravitational force, which is a type of action at a distance force.