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 force concept of force and its unit force - push or pull forces

When two forces,applied on an object, equal and opposite,then the forces

  1. May move the object

  2. May stop the object

  3. May move the object and also cause a change in its shape

  4. Do not move the object but may cause a change in its shape.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

A force may not always succeed in bringing a change in the state of motion of an object.

When equal and opposite force is applied it do not let the body to move,but cause change in shape of the body.

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

When a small body hits a very large body,then the

  1. Forces acting on both the bodies are different in magnitude but direction is same.

  2. Forces acting on both the bodies are equal in magnitude and direction is also same

  3. Forces acting on both the bodies are equal in magnitude but opposite in direction

  4. Forces acting on both the bodies are different and directon is also opposite to each other
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

When a small body hits a very large body,then the forces acting on both the bodies are equal in magnitude but opposite in direction.However the effect (of force)produced in the small body is very large as compared to the effect of (the equal)force on the larger body.

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

When three forces of 50N, 30N and 15N act on a body, then the body is 

  1. At rest

  2. Moving with a uniform velocity

  3. In equilibrium

  4. Moving with an acceleration
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Here all the three force will not keep the particle in equilibrium$,$

So$,$ the net force will not be zero and the part particle will move with an acceleration$.$
Hence,
option $(D)$ is correct answer.

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

Raj was riding his bicycle.After some time, he got tired and stopped paddling the cycle. The cycle stopped after traveling some distance.Which laws of motion helps us to explain this phenomenon?

  1. First law of motion.

  2. Second law of motion.

  3. Third law of motion

  4. Law of conservation of energy.
Reveal answer Fill a bubble to check yourself
A,B,C Correct answer
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 static electricity explaining static electricity charging by induction electric charges and fields

If a body is charged by rubbing it, its weight _________.

  1. Remains precisely constant

  2. Increases slightly

  3. Decreases slightly

  4. May increase or decrease slightly
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

If a body is charged by rubbing it, then it may lose or gain electrons. Since electrons have a mass of $(9.1\times 10^{-31} :Kg)$. So, a slight weight may increase or decrease slightly.

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.