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 physics measurements and units kinds of units fundamental quantities standardized measurement

Which of the following physical quantity is different form others ?

  1. Displacement

  2. Velocity

  3. Force

  4. Kinetic energy
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Displacement, force, and velocity are vector quantities as they require direction as well as the magnitude for their representation but the kinetic energy is a scalar quantity as it does not require direction for its representation.

Multiple choice physics gravitation: planets and satellites weightlessness application of newton's law of motion escape velocity

Weightlessness experienced while orbiting the earth in a spaceship is the result of

  1. Inertia

  2. Accelaration

  3. Zero gravity

  4. Centre of gravity
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Weightlessness means that there is no reaction on a body from the floor. Since both the artificial satellite & the astronaut have same centripetal acceleration (as in a lift; which is falling freely, we does not feel any weight, because both lift & we fall with same acceleration). so the astronaut does not feel any weight inside the space craft

Multiple choice physics gravitation: planets and satellites weightlessness application of newton's law of motion escape velocity

Weightlessness experienced in a spaceship is due to

  1. absence of of inertia.

  2. absence of gravity.

  3. absence of accelerating force.

  4. free fall of the spaceship.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

It is a misconception that there is no gravity in space.
An astronaut experiences weightlessness due the fact that as the spacecraft revolves around the Earth, the astronaut is continuously falling towards the Earth. This is similar to what a person standing in an elevator, that is falling freely, would experience. The person would be weightless as the elevator falls.

Multiple choice physics energy and its forms idea of energy introduction to work and energy work and energy

The negative of the work done  by the conservative internal forces on a system equals to the change in 

  1. total energy

  2. Kinetic energy

  3. Potential energy

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

The negative of the work done  by the conservative internal forces on a system equals to the change in potential energy


Hence, correct answer is option $C$

Multiple choice physics the essence of change forms of energy and energy conservation energy for everything forms of energy

Which of the following may no be conserved for an isolated system 

  1. Energy

  2. Potential energy

  3. Mechanical energy

  4. Kinetic energy
Reveal answer Fill a bubble to check yourself
B,C,D Correct answer
Explanation

In an isolated system only $T.E$ is conserved $M.E$ can not be conserved in case of inelastic collision$.$ Some energy is converted into heat$.$ and sum of $P.E,K.E$ and lost energy remains const$.$

Hence,
option $b,c,d$ is correct answer.

Multiple choice physics universe and space heliocentric model introduction to gravitation introduction to gravity

------------ is the force of attraction between any two bodies in the universe.

  1. Gravitation

  2. Polarity

  3. Induction

  4. Joule
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Any two objects attract each other with a force $F _g=\dfrac{GMm}{R^2}$ where $G$ is the gravitational constant, $M$ and $m$ the masses of the two bodies and $R$ is the distance along the line joining their centre of mass

Multiple choice physics universe and space heliocentric model introduction to gravitation introduction to gravity

The gravitational force is a

  1. contact force

  2. action at a distance force

  3. non contact force

  4. both (B) and (C)
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Gravitational force is a action distance force because it can interact with an object even they are not in physical contact with each other, yet they are able to exert a push or a pull despite their physical operation. Hence gravitational force is a action at a distance force.

Gravitational force is also a non contact force because non contact force is a force which acts on an object without coming in physically contact with each other which is similar to a action at a distance force.

Multiple choice physics universe and space heliocentric model introduction to gravitation introduction to gravity

The weakest forces of interaction among all classified forces are

  1. electrostatic forces

  2. gravitational forces

  3. weak nuclear forces

  4. electromagnetic forces
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Gravitational force is the weakest of all the forces because its coupling constant is small in value. Gravity cannot be felt in day to day life because of the huge universe surrounding earth. Electromagnetic force is the strongest of all  force as it deals with microscopic particles.

Multiple choice physics universe and space heliocentric model introduction to gravitation introduction to gravity

A force which produces an acceleration in a body equal to acceleration due to gravity on earth, when the body has a unit mass is called

  1. Gravitational unit of force

  2. Gravity force

  3. Both

  4. None
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Definition of gravitational unit of force: A force which produces an acceleration in a body equal to acceleration due to gravity on earth, when the body has a unit mass is called gravitational unit of force.

Multiple choice physics universe and space heliocentric model introduction to gravitation introduction to gravity
State whether true or false.
Gravitational forces can also be repulsive like that of electrostatic forces.

  1. True

  2. False
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Gravitational force, $F=\cfrac { G{ M } _{ 1 }{ M } _{ 2 } }{ { R }^{ 2 } } $

Now the mass of the objects can not be opposite (i.e., mass cannot be negative), thus, the nature of the force cannot be repulsive like that of electrostatic force.