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 types of energy law of conservation of energy the law of conservation of energy work, energy and machines

The law of conservation of energy implies that the:

  1. Total mechanical energy is conserved

  2. Total kinetic energy is conserved

  3. Total potential energy is conserved

  4. Sum of all kinds of energies is conserved
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Law of conservation of energy implies that energy can neither be created nor destroyed, but can merely be transfered from one form to other. These forms are varied. Thus, when considering all forms of energy,(including workdone) the total sum never changes.

Multiple choice physics types of energy law of conservation of energy the law of conservation of energy work, energy and machines

When an object falls freely towards the earth, then its total energy :

  1. Increases

  2. Decreases

  3. Remains constant

  4. Can't say
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Since the ball is in free-fall, the only force acting on it is gravity. Therefore, we can use the principle of conservation of mechanical energy - initially the ball has potential energy and no kinetic energy.
As it falls, its total energy (the sum of the KE and the PE) remains constant and equal to its initial PE.
Hence, option C is correct.

Multiple choice physics types of energy law of conservation of energy the law of conservation of energy work, energy and machines

When you push a huge rock with all your might and fail to move it,then:

  1. transfer of muscular energy to stationary rock does not take place

  2. low transfer of muscular energy to stationary rock take place

  3. high transfer of muscular energy to stationary rock take place

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

Transfer of muscular energy to stationary rock does not take place as the displacement is zero so the work done by you is zero, avoiding any conversion of energy.

Multiple choice physics types of energy law of conservation of energy the law of conservation of energy work, energy and machines

A freely falling object eventually stops on reaching ground. What happens to its potential and kinetic energy while falling?

  1. Potential energy decreases and Kinetic energy increases

  2. Potential energy increases and Kinetic energy increases

  3. Potential energy increases and Kinetic energy decreases

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

Potential energy decreases and Kinetic energy increases when the object is falling but the total mechanical energy remains constant at every instant.

Multiple choice physics kinematics motion around us motion and rest moving things around us

When a body is at rest, it is obeying :

  1. Principle of conservation of energy

  2. Newton's first law

  3. Ohm's law

  4. Newton's second law
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Newton's first law states that; "An object at rest stays at rest and an object in motion stays in motion with the same speed and in the same direction unless acted upon by an unbalanced force".Thus, body continues in it's state of rest as there is no external force on it,

So, option B is correct.

Multiple choice physics kinematics motion around us motion and rest moving things around us

If a body does not change its position with respect to its surroundings, the body is said to be at rest.

  1. True

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

The body when considered in frame of reference of surroundings, then zero relative velocity means it is at rest. So. statement is true.

Multiple choice physics kinematics motion around us motion and rest moving things around us

In which of the following cases , the net force is zero?
I) A ball freely falling from a certain height
II) A cork floating on the surface of water
III) An object floating in air

  1. I and II only

  2. II and III only

  3. III and I only

  4. I, II and III
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

A freely falling object has a net force equal to its weight (gravity), so it is not zero. A cork floating on water and an object floating in air (like a balloon) are in equilibrium where the upward buoyant force equals the downward gravitational force, resulting in a net force of zero.

Multiple choice physics kinematics motion around us motion and rest moving things around us

In the state of equilibrium
I) Net force is zero
II) Body at rest will continue to be in its state of rest
III) Body moving with uniform velocity will continue to be in its state of uniform velocity
IV) Body with linear momentum $\vec{p}$ will continue to have the same momentum $\vec{p}$.

  1. all are correct

  2. I, II, III are correct

  3. II, III, IV are correct

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

In a state of equilibrium, the net force is zero, which implies no acceleration. By Newton's first law, an object at rest stays at rest, and an object in uniform motion continues at that velocity (constant momentum), making all statements correct.

Multiple choice physics kinematics motion around us motion and rest moving things around us

Symmetry of the laws of nature with respect to translation in time give rise to

  1. Conservation of linear momentum

  2. Conservation of angular momentum

  3. Conservation of cahrge

  4. Conservation of energy
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Time translation symmetry gives rise to the conservation of energy.

Space translation symmetry gives rise to conservation of momentum.

Rotational symmetry gives rise to conservation of angular momentum.

The conservation law associated with this symmetry is the conservation of electrical charge.

 

Multiple choice geography in search of the source of wind variations in atmospheric pressure properties of air pressure belts

The speed and the direction of wind are based on which of the following? 

  1. Pressure gradient force

  2. Coriolis force

  3. Friction

  4. All of the above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Pressure gradient force,

winds balanced by the Coriolis and Pressure Gradient forces. An air parcel initially at rest will move from high pressure to low pressure because of the pressure gradient force (PGF). ... As the wind gains speed, the deflection increases until the Coriolis force equals the pressure gradient force.
Coriolis force,
The Coriolis effect influences wind by deflecting its path to the right in the Northern Hemisphere. The sequence of weather satellite images shows that the actual wind direction is from the southwest. The satellite images show atmospheric motion over the northern Pacific Ocean for a 36-hour period.
Friction,
 Winds affected by friction. Geostrophic wind blows parallel to the isobars because the Coriolis force and pressure gradient force are in balance. ... As we move higher, surface features affect the wind less until the wind is indeed geostrophic.

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

Which of the following cannot be considered an example of precession?

  1. A spinning top

  2. A spinning wheel

  3. Rolling ball

  4. Spinning of the earth
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Spinning of top, spinning wheel and spinning of the earth are purely rotational motion whereas rolling ball exhibits both rotational motion as well as translational motion. As precession is described by rotational motion only, thus rolling of ball cannot be considered as an example of precession.