Physics · 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 physics force concept of force and its unit force - push or pull forces

Suppose a body that is acted on by only two forces, is accelerated. For this situation, mark the correct statement :
( Initial Velocity is non zero and in same direction as acceleration  ) 

  1. The body cannot move with constant speed

  2. The velocity can never be zero

  3. The sum of two forces cannot be zero

  4. The two forces must act in the same line
Reveal answer Fill a bubble to check yourself
A,B,C Correct answer
Explanation

If the body is accelerating, then there is a net force which drives the body. Since the body is accelerating, velocity can not be zero or moving with a constant speed. 
It is not necessary that the two forces must act in the same line however they may act in the same line.

Multiple choice physics mechanics concept of force and its unit force - push or pull forces

What happens when two forces in the same direction, are applied on an object?

  1. Forces add up.

  2. Forces subtract.

  3. Resultant force is the division of forces.

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

When two forces are applied on a object in the same direction, forces added up and net force increases.

Multiple choice physics mechanics concept of force and its unit force - push or pull forces

When you and your friend push a table in opposite directions, it becomes difficult to move. This is because:

  1. the net force becomes the sum of the two forces.

  2. the net force becomes the difference of the two forces.

  3. the table becomes heavier.

  4. the table becomes lighter.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

When two forces are applied in opposite directions, the net force becomes the difference of the two. So, the net force becomes small and the table becomes difficult to move.

Multiple choice physics mechanics concept of force and its unit force - push or pull forces

In the game of tug-of-war, the team that pulls the rope harder wins the game. This is because:

  1. the rope moves in the direction of larger force.

  2. the rope moves in the direction of the smaller force.

  3. the rope does not move at all.

  4. the rope moves in the direction of product of the forces.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

In a game of tug-of-war, teams apply forces in terms of pulls on the rope. On the rope, two pulls act in opposite directions. The net force becomes the difference of the two forces (pulls) and the rope moves in the direction of the larger force (pull).

Multiple choice physics mechanics concept of force and its unit force - push or pull forces

When you and your friend pushes heavy table in the same direction, it becomes easier to move. This is because:

  1. the net force is the sum of forces.

  2. the net force is the difference of forces.

  3. the table becomes lighter.

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

When you and your friend pushes heavy table in the same direction, the force applied by you and your friend get added. So, applied forces sum up to get a larger force. Hence the table moves easily.

Multiple choice physics forces - vectors and moments centre of gravity turning effects of forces acceleration due to gravity

Can the centre of gravity be situated outside the material of the body ?

  1. Yes

  2. No

  3. Can't say

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

Yes, it can. For example, in case of a ring, it is situated at the centre of that circle. But the material is only along the circumference. Hence centre of gravity is situated outside the material of the body.

Multiple choice physics motion of system of particles and rigid bodies centre of gravity turning effects of forces forces - vectors and moments

What is the position of centre of gravity of a cylinder?

  1. At the center of base circle

  2. At the center of top circle

  3. Cannot be determined

  4. At the mid point on the axis of cylinder
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Centre of gravity means a point from which the weight of a body or system may be considered to act. In uniform gravity it is the same as the centre of mass. For regular shaped bodies it lies at the centre of the that particular body. Hence for a cylinder centre of gravity lies at the midpoint of the axis of the cylinder.

Multiple choice physics pressure common consequences of the atmospheric pressure atmospheric pressure and its consequences important points about atmospheric pressure


when an air particle speeds up, it actually pushes            . Complete the sentence

  1. Less

  2. More

  3. Inside

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

According to Bernoulli's theorem        $ P + \rho gh+ \dfrac{1}{2}\rho v^2= constant$
$\implies$  When $v$ is more, then pressure $(P)$ is less.
Thus when an air particle speeds up, it actually pushes less.

Multiple choice physics measurements and units some examples of derived units fundamental and derived quantities fundamental and derived units

The effect of an impulse force on the body is measured only in terms of its

  1. Force

  2. Moment of momentum

  3. Impulse

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

The effect of an impulse force on the body is measured only in terms of impulse. If a moving object is stopped by an impact, the change in momentum of the object occurs. This change in momentum is called the impulse.

Multiple choice physics measurements and units some examples of derived units fundamental and derived quantities fundamental and derived units

Which of the following has derived dimension?

  1. Velocity

  2. Acceleration

  3. Density

  4. All of the above

Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The fundamental quantities are basically mass, length,  time etc. Velocity is defined as the rate of displacement with respect to time. Displacement has dimensions same as that of length. Velocity is a derived quantity. Acceleration is defined as the rate of change of velocity with respect to time. This is how when acceleration is dependent on time and velocity. It is also a derived quantity. Density is defined as the mass of a unit volume of a substance. Volume has the dimension of the cube of length. Hence density is also a derived quantity.

Multiple choice physics energy management solar power plant production of electricity from solar energy solar equipment solar energy and its applications

In a mechanically isolated system, which interaction is allowed?

  1. Mass flow

  2. Work

  3. Heat flow

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

A mechanically isolated system is that , which cannot do work on environment and there is no exchange of mass between system and environment but exchange of heat is allowed between system and environment .