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 rigid body dynamics motion of rigid body rigid body equilibrium of a rigid body

Ram says, $'A$ body may be in pure rotation in the presence of a single external force, 'Shyam says, 'This is possible only for a rigid body', then:

  1. Ram's statement is correct

  2. both statements are correct in different situations

  3. both statements are wrong

  4. both statements are stated by physicists
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

A single external force acting on a body will cause both translational and rotational acceleration if the line of action does not pass through the center of mass. A body can be in pure rotation only if the net force is zero or if the body is constrained (like a hinge), so Ram's statement is incorrect. Shyam's statement is also incorrect because pure rotation is not exclusive to rigid bodies, and a rigid body can still undergo translation under a single force.

Multiple choice physics rigid body dynamics motion of rigid body rigid body equilibrium of a rigid body

Any point on the circumference of a rigid body which is rolling without slipping undergoes :

  1. a circular path

  2. an elleptic path

  3. a cycloid path

  4. an parabolic path
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Any point on the rigid body, undergoing rolling without slipping, will have linear and angular speed, such that

$linear\ speed = distance\ from\ CoM \times angular\ speed$

Such particles follows cycloid path.

Multiple choice physics rigid body dynamics motion of rigid body rigid body equilibrium of a rigid body

Rolling without slipping is an example of

  1. Rotation

  2. Translation

  3. Rotation with translation

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

When a body is rolling without slipping on the ground, its center of mass exhibits translational motion whereas the body exhibits rotational motion in its center of mass frame. Thus rolling body exhibits both translational motion as well as rotational motion.

Multiple choice physics force and newton's laws of motion concept of inertia galileo's law and inertia mass and inertia

While dusting a carpet, we give a sudden jerk or beat with a stick because :

  1. Inertia of rest keeps the dust in its position and the dust is removed by movement of carpet away.

  2. Inertia of motion removes dust.

  3. No inertia involved in process.

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

When carpet is given sudden jerk, due to inertia dust particles does not change position, while carpet moves.

Thus dust particles gets separated from carpet.
So, Option A is correct. 

Multiple choice physics force and newton's laws of motion concept of inertia galileo's law and inertia mass and inertia

Which of the following has more inertia ___

  1. 5Rp coin and 2Rp coin

  2. 2Rp coin and 3Rp coin

  3. 10Kg iron

  4. None of these
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
Inertia depends upon the mass of the body. If the mass is more, inertia is more and vice versa. 10kg iron has more mass than 5Rp coin and 2 Rp coin thus its inertia is also more.
So, the correct answer is '10kg iron'.
Multiple choice physics force and newton's laws of motion concept of inertia galileo's law and inertia mass and inertia

When a tree with a flexible stem is shaken vigorously,its fruits and leaves fall  own.This phenomenon can be explained by making use of

  1. Newton's first law of motion

  2. Newton's second law of motion

  3. Newton's third law of motion

  4. Law of conservation of momentum
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

 

There are three types of inertia:
1. Inertia of rest: This is the resistance offered by the body to remain in rest unless an external force is not applied on the body. Eg. : If a carpet is beaten with a stick then the dust particles due to inertia of rest tends to remain in rest while the fibres of carpet becomes in motion.


2. Inertia of direction: This is the resistance offered by the body to change its direction unless an ext. force is not applied on the body. Eg : If a bus takes a turn then passengers sitting in tends to remain in the same direction in which the bus was travelling before.


3. Inertia of motion: The resistance offered by the body to change its uniform motion. Eg : If a bus stops suddenly then the passengers fall forward due to inertia of motion

So when we shake a tree, due to inertia of motion the fruit tries to remain in motion. Due to which it gets detached from the branch and falls.

Multiple choice physics force and newton's laws of motion concept of inertia galileo's law and inertia mass and inertia

Why can dust be removed from a carpet by shaking it, or by beating it with a stick?

  1. Because of inertia of rest

  2. Because of inertia of motion

  3. Because of inertia of direction

  4. Because of momentum
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

When the carpet is shaken or beaten by a stick, then the carpet moves back but the dust remains still due to inertia of rest and hence the dust particles get separated out.