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 force exerted by collision collisions work, energy and power mechanics physics

During any collision

  1. Momentum is conserved

  2. Linetic energy is conserved

  3. Both conserved

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

During any collision, the momentum is conserved but the kinetic energy is not. This is because during collision, a part of kinetic energy is converted into heat sound energies.

Multiple choice force exerted by collision collisions work, energy and power mechanics physics

For two body system, the forces they apply on each other during collision with each other are

  1. external forces on the system

  2. internal forces within the system but external forces on each body

  3. external forces on the system but internal forces on each body

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

When we consider two body as one system, any interaction between them is internal. But when we consider one body (as system), the force applied by the other body is external force.

Multiple choice force exerted by collision collisions work, energy and power mechanics physics

Line which is common normal for surfaces in contact during impact is known as

  1. Line of impact

  2. Line of collision

  3. Line of energy

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

Line which is common normal for surfaces  in contact during impact is known as line of impact. This is the line along which internal force of collision acts during impact.

Multiple choice chemistry air, winds and cyclones the concept of bernoulli's principle air exerts pressure wind and pressure variations in atmospheric pressure wind and rain uneven heating of earth

A piece of paper is kept on the table.  You have to lift it from the table by blowing high-speed air over it. In which direction will you blow the air?

  1. Sideways

  2. In the upward direction

  3. In the downward direction

  4. In the upward direction below the table
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
In order to lift the paper up from the table we need to blow air in sideways.
Multiple choice fluid dynamics option b: engineering physics physics

Choose the wrong statement.

  1. Viscous force always supports the motion.

  2. A denser fluid always more viscous than a less dense fluid.

  3. Any object cannot have a velocity after a sufficient long time more than its terminal velocity in a given fluid.

  4. If a body is at rest in a fluid then the viscous force on it is zero.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Viscous force is a frictional force which opposes the relative motion between liquid molecules. Terminal velocity is the velocity attained by the particle when net force on it becomes zero the body cannot have more velocity than terminal velocity in respective fluid.

Multiple choice standardized measurement measurement of physical quantities need of unit for measurement measurements and experimentation physics

In a tug-of-war between the teams A and B, the rope breaks at a point which is nearer to A. Then

  1. A has applied more force

  2. B has applied more force

  3. A and B both have applied same force

  4. Neither has applied any force
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

In a tug-of-war, the tension throughout the rope is uniform. If the rope breaks, it is due to a structural weakness at that point, not because one side pulled harder than the other.

Multiple choice standardized measurement measurement of physical quantities need of unit for measurement measurements and experimentation physics

Which of the following pairs has not the same dimension?

  1. Stress; pressure

  2. Force; surface tension

  3. Impulse; linear momentum

  4. Frequency; angular velocity
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Surface Tension$ (T) =\dfrac{ Force}{Length}$  . . . . . (1)

Since, $Force = Mass \times Acceleration$

And, $Acceleration = \dfrac{velocity}{ time}= [L T^{-2}]$

$\therefore $ The dimensional formula of force $= M^1L^1T^{-2}$ . . . . (2)

On substituting equation (2) in equation (1) we get,

Surface Tension $(T) = \dfrac{Force}{  Length}$

Or, $T=\dfrac{[M^1L^1T^{-2}]}{[L^{1}]}=M^1T^{-2}$ 

Therefore, surface tension is dimensionally represented as $[M^1T^{-2}]$


Dimension of force $=M^1L^1T^{-2}$

So the dimension of force and surface tension are different.

Multiple choice chemistry substances in the surroundings - their states and properties elastic behaviour of solids elastic and plastic substances properties of substances

Fill in the blank.
In a technical sense a substance with a ________ elasticity is one that requires a ______  force to produce a distortion-for example, a steel sphere. 

  1. high, small

  2. high, large

  3. low, large

  4. low , small
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

According to Hooke's law, within elastic limit,

    $E=\dfrac{stress}{strain}$$=\dfrac{deforming\ force}{(area\times strain)}$ 
It means higher the elasticity, larger will be the required deforming force.
Hence, in a technical sense a substance with a high elasticity is one that requires a high force to produce a distortion.

Multiple choice physics properties of material substances elastic behaviour of solids elastic and plastic substances properties of substances

At yield point, Hooke's law doesn't hold good

  1. True

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

The yield point is the point on a stressstrain curve that indicates the limit of elastic behavior and the beginning of plastic behavior. Yielding means the start of breaking of fibers.

Thus, Hooke's law dosent hold good in this region, as stress is not proportional to strain in this region

Multiple choice chemistry substances in the surroundings - their states and properties elastic behaviour of solids elastic and plastic substances properties of substances

An elastic metal rod will change its length when it

  1. falls vertically under its weight

  2. is pulled along its lengthy by a force acting at one end

  3. both

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

An elastic rod changes its length when subjected to a tensile force (being pulled). Falling vertically under its own weight also causes stress and potential elongation, but pulling is the standard demonstration of elastic deformation.